P0171 Trouble Code: System Too Lean Bank 1 Diagnosis

Рет қаралды 2,576,268

5 жыл бұрын

In this video, I show you how I troubleshoot a Check Engine Light (CEL) / Diagnostic Trouble Code (DTC) P0171, System Too Lean Bank 1. The exact vehicle in video is a 2002 Toyota Tacoma standard cab 4 cylinder pickup truck. The techniques shown can be used on many vehicles, not just Toyotas.
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The Big Dog50001 Automotive Channel recommends safe practices when working with power tools, in on or around automobiles or other vehicles, automotive lifts, lifting tools, jack stands, electrical equipment, automotive modules and systems, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video.
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Пікірлер: 1 900

@m2svirtual384 3 жыл бұрын

It would be impossible to add up all the hours of auto repair videos I've watched over the last 8-10 years. THIS ONE, though, MAN!! In only 46 mins... I'm speechless at how easily I absorbed every concept and it made logical sense. I was starting to diagnose ahead of you! You sir, not only have a gift of mechanics and troubleshooting, you have an even greater gift of TEACHER. Never boring, just a concise step-by-step stream of logical information. I stood at a standing ovation at the end of this video, and I cannot thank you enough for the education you imparted upon me. Thanks Dawg!

@john3tim 2 жыл бұрын

Could not have said it better. Very clear and logical.

@likits1999 2 жыл бұрын

I agree. It was like being in a classroom with an great instructor.

@dennissalisbury496 Жыл бұрын

Me too!

@coleimhuelsen Жыл бұрын

Agreed

@michaelpigeon3591 Жыл бұрын

That was one the best and formative Video I’ve ever watched. Thank you 45:52

@TheBigOPossum1 Ай бұрын

One of the BEST diagnostic and troubleshooting videos I have ever seen. Thouroughly and easy to understand explanation of potential problems, causes and fixes for the P1071 code. BRAVO!!! At 77 years of age and very much an old school mechanic, I have been trying to self educate myself on the more modern engine design and theory. Your video is JUST WHAT this old guy needed. THANK you so much.

@BigDog50001 Ай бұрын

Thank you, I appreciate the comment!!

@cal48koho Жыл бұрын

hard to overstate how sharp this guy is. Beautiful explanation . This is at a high level expert mechanic level!

@keninswed 7 ай бұрын

Totally agree man knows his craft. He is not a change this item kind of mechanic but a motor doc.

@SDMev1982 3 жыл бұрын

Some of the best 46 minutes I’ve ever spent.

@BigDog50001 3 жыл бұрын

Thank you, I appreciate the comment!

@sandiego7625 2 жыл бұрын

@billlincoln6087 5 жыл бұрын

THE BEST MAF DIAGNOSTICS ON THE INTERNET.

@BigDog50001 5 жыл бұрын

Thank you for the comment!

@Sheeeeeeeeeeeeiiitt 4 жыл бұрын

I agree! He does an excellent job communicating in such a way that his message doesn’t get lost in translation. Very informative, relevant and concise. Thanks for sharing the content Big Dog50001 Automotive.

@thomasrouse9146 3 жыл бұрын

@NoneFB 2 жыл бұрын

@@BigDog50001 I wonder how much that Vantage is....

@princekodeys3028 2 жыл бұрын

000000

@stupagia26 Жыл бұрын

i don't normally respond to videos, but I almost felt like this gentleman was standing next to me and showing me all this in person and not shouting at me. Best of all is I appreciated how he explained everything he was looking at and what significance it had in terms I could easily follow along with. Turns out he lives in my neck o' the woods. Thanks Big Dog! I promise I won't tell, Scotty! :{>

@michaelpigeon3591 Жыл бұрын

Agreed

@evandrewmartinez1 3 жыл бұрын

This video made me feel like I already fixed my po171 and I haven't even went outside yet

@BigDog50001 3 жыл бұрын

lol

@jrnycg3589 3 жыл бұрын

😂😂

@randallmcclain6368 3 жыл бұрын

Lol I know what you mean..

@dougsanders6034 3 жыл бұрын

Great informative VIDEO! I have found that EGR valves , PCV valves , and IAC valves are notorious for sources of vacuum leaks.

@juancortez2067 3 жыл бұрын

Off

@robertlardon3782 2 жыл бұрын

The most thorough and insightful "how-to diagnostic" car video I've seen! The 46 mins went fast with no fluff; just great information. Big Dog is a great mechanic and teacher!

@BigDog50001 2 жыл бұрын

I appreciate the comment, thank you!

@netwonc 5 жыл бұрын

The very best analysis of this problem. Shows how to test all systems. Thanks for sharing your knowledge with us.

@BigDog50001 5 жыл бұрын

Thank you for the comment, I really appreciate it!

@user-sq8rs2lc9c 6 ай бұрын

THE MOST DETAIL DIAGNOSTICS PROCEDURE PRESENTED IN THIS CASE STUDY. SO BENIFICAL AND ACCURATE. THROUGH DIAGNOSTICS 1) VACUUM LEAK 2) BAD MAF 3) BAD BRAKE BOOSTER. ALL 3 STEPS ARE SUPPOERTED WITH STFT AND LTFT. JUST PERFECT WORK.

@michaelclayton4703 3 жыл бұрын

As a driveability expert myself, you did an absolute awesome job, for not only a layman, but also experienced technicians! I am not ashamed to say I picked up a few tips too! Outstanding!

@BigDog50001 3 жыл бұрын

Awesome, I appreciate the comment, thanks!

@ericjernigan655 2 жыл бұрын

Hands down the best diagnostic video I've ever watched on KZfaq (and I've watched a ton). I learned more in that 46 minute video than all the others combined. Outstanding teaching video.

@tonyfox1434 3 ай бұрын

I watch and learn diagnostic trouble codes daily and to be honest, your way of using a cheap code reader with live data was the most interesting and informative video I have seen in a long time. Thank you, and all on a cheap device !!

@richardr5774 5 жыл бұрын

This is a great teacher! I now understand fuel trims, something that was a mystery to me even after watching hours and hours of "SMA" ! Thank you , Big Dog , for making it so easy to understand, I"m now a subscriber !

@BigDog50001 5 жыл бұрын

SMA is awesome. Thanks for the comment, I appreciate it!

@1guardia 2 жыл бұрын

I totally agree. Well explain!

@alia176 3 жыл бұрын

This was an EXCELLENT video, good job Dave. You're a good speaker and a camera operator. You dumbed down how an ECU manages the engine to a level that I think most of us will grasp easily. Your steps are logical and easy to follow. Thanks for taking the time to make this video.

@BigDog50001 3 жыл бұрын

Thanks 👍!

@studhammer 4 жыл бұрын

Wow! This was the most educational video I’ve ever seen. I just got the same error code on my Camry and this video shows me how to troubleshoot. You sir are an incredible teacher!

@BigDog50001 4 жыл бұрын

I appreciate the comment, thanks!

@rubbermalet9292 5 жыл бұрын

this is actually "prime time info" bro im a retired mechanic with many years in the industry - i still practice with neigbs & friends' cars lol- and the way you'd explain everything regarding this issue is basically the same way automobile instructors do at automechanic schools & at college level too, very professionaly w/o any gimicks thank you for taking this time and to help us to understand the technicalities involved within 💖

@BigDog50001 5 жыл бұрын

Thank you for the comment, I really appreciate it!

@ivaneatoniii5025 2 жыл бұрын

I totally agree, I work on my own autos, and my family as well. I am a Grad of T-Ten for Lexus and Toyota. I am not working in the field anymore. I make more money with my current path. That being said. My Instructors should be made to sit with you. So they can teach the new guys correct ways to learn diagnostics and breaking down the steps. I say that because I was dumbfounded when in the middle of a class on Finding a obvious fuel delivery issue. The instructor refused to even entertain a possible pirate air issue. While he set it up to be fuel issue from a under pressure of fuel being delivered. You should always go simple/Cheaper/faster diagnostics before you go to harder issues. pulling a vacuum test on a fuel rail is a little harder then watching fuel trims and alteast checking off not pirate. Great job. Also I disagree with only one of Rubber malets comments. You know you trained that damn fly.. It was a gimick fly!!!

@mikeb7887 5 жыл бұрын

This video is one of the best full explanations of the diag process I have seen. Really well done and very clear to understand. You tied in fuel trim, scan tool, O2"s, vacuum gauge, and scope to clearly show us what is going on with this engine. Thank you! Mike B Tarrytown

@BigDog50001 5 жыл бұрын

I appreciate the comment, thanks!

@raygooding9935 Жыл бұрын

@@BigDog50001 this video has inspired me to become a mechanic. Good job bro. Thanks

@spiketaterman5181 5 жыл бұрын

Thanks for this! Was driving my car over rough roads, and the check engine light came on. It threw a P0171 code. Once home, I popped the hood and saw this plastic chamber thing had fallen off the air intake throat pipe DOWNSTREAM from the MAF sensor. Popped it back on and tightened clamp with a screwdriver and good to go! I love youtube university...

@BigDog50001 5 жыл бұрын

Good to hear you got it fixed! Thank you for the comment!

@tinapalmisano7554 4 жыл бұрын

Absolutely love your video! Cannot explain how much this will help me. Actually understanding step by step the information under those codes, is priceless!

@BigDog50001 4 жыл бұрын

I appreciate the comment, thank you!

@BigAlWillis 5 жыл бұрын

I've watched many car repair videos over the years. This one ranks up there with the very best. excellent!

@BigDog50001 5 жыл бұрын

Thank you for the comment, I appreciate it!

@1guardia 2 жыл бұрын

This guy is the best!!

@Borealis2007 5 жыл бұрын

You set the bar so high for the average uneducated mechanic who will have you replace part after part to fix an elusive problem.

@BigDog50001 5 жыл бұрын

Thank you for the comment, I appreciate it!

@weldingjunkie 4 жыл бұрын

Most of the time when the pcm is dumping fuel in like that it’s an air problem and visa versa.

@randallmcclain6368 3 жыл бұрын

I'm guilty of throwing parts at the car I have now but I've been working on old American cars my whole life and now at 40 I'm looking for chokes and floats, points, condensers, caps and rotors and I'm like omg...where the hell have I been? And where the hell did they go?

@swilson317 3 жыл бұрын

I have a 2002 Miata. Multiple mechanics have replaced parts and smoke tested. We just replaced the injectors! Unfortunately, It’s still throwing the P071! Argh!

@1guardia 2 жыл бұрын

Is there a way to give you 10,000 likes ?👍

@AirmanJH Жыл бұрын

Very thankful for your explanation of the data. Lots of videos out there about vacuum leaks, but this is the first I’ve seen that explains what all those numbers mean and how to use that info. Much appreciated!

@LAYLAANDSZA 2 жыл бұрын

I don't think anyone could explain how to diagnos a lean condition better than BigDog50001 did in this video! Great job, and I truely gained a huge amount of knowledge, thanks so much!

@wendwllhickey6426 Жыл бұрын

I had same po 171 and it turned to be a maf sensor had only 1.2 ohms and need to be 2.5 to 3.5 ohms on sensor change out sensor fixed it

@nothingspecial6248 Жыл бұрын

@darrinfaulkner8911 3 жыл бұрын

I sat and watch this whole video on my 1 hour lunch break and must say this mechanic is like a school teacher that was teaching myself the student.Great video and he was very articulate and professional in narrowing down the problem.The explaining of the OB2 reader was on point as well because I use mines alot but dont understand some of the word play on the tool until you explained it.Thumbs up to your video👍...

@BigDog50001 3 жыл бұрын

Glad it was helpful, thank you for the comment!

@candicekillmer4694 3 жыл бұрын

This video helped more than any other video I've watched trying to figure out how to fix the p0171 code. And I'll be dammed if it isn't a freaking brake booster leak. We have Been trying to find this vacuum leak for 3 months and couldn't find anything. Replaced many parts trying to fix /find the vacuum leak. A lot of money into repairs that weren't needed and a waste of money. Thank you for going through every possible reason to get this code. This car was pissing me off and I've become more of a mechanic than I ever wanted to be. You just saved my scion tc from going to the scrap yard. Thank you!

@BigDog50001 3 жыл бұрын

👍

@darrinfaulkner8911 3 жыл бұрын

You sound like me with my car and all these repairs I've done and it was my booster.No regrets though because the market value on my car went up and I've became a better mechanic that saved money for future repairs at rip off mechanic shops...

@chiya2006 Жыл бұрын

This diagnostic is very precious to everyone. I learned hard way by changing complete ignition coils & spark plugs just to find out that the problem was purge valve and gas cap which I changed later, made the car running again. Yes I suspect I have to go after in details just like what you outlined here as I know I still have issues with either a vacuum leak, sensor problem, maf problem or fuel filter/pump. Thank you so much for taking from your previous time to give us most needed info . Thank you 🙏

@RxRau-kg9ot Ай бұрын

I thought I'd be skipping through 45 minutes of video, but every minute was a gold nugget of information. Very happy to see you demonstrate a $20 scan tool all the way to a Snap on.

@retiredsoon1365 2 жыл бұрын

Had a similar problem on my old Toyota Yaris. using an a very basic analyser fault codes only. I followed your advise and found a damaged air line going to the throat of the Mass airflow. Replaced with a generic hose now idle is restored and my old car lives to fight another day. Thank you for your video.

@phamster18 3 жыл бұрын

learned so much , from how to know , to fixing and using your experience and showing the results. your data driven fix was so perfect to watch.. didn't waste 40 mins watch, invested in 40 mins for life time problem solving techniques... keep up this great work

@BigDog50001 3 жыл бұрын

Glad it was helpful, thank you for the comment!

@josetovar9222 2 ай бұрын

Your video just saved me hundreds of dollars! You’re THE man! What a great teacher!

@BigDog50001 2 ай бұрын

Thanks for the comment 👍!

@ccrobinpeg 3 жыл бұрын

Came across this channel by accident while surfing youtube on my smart TV. "Diagnosis" sucked me in. I'm a retired elect tech, computer geek, self-schooled mechanic, ham, engine builder, etc. Watching the step by step trouble -shooting process kept me glued to the screen. I learned what some of those scanner screen displays meant and their interactions. Congrats on the clear explanations of each branch of the TB tree. Learned a lot! Thanks!!

@BigDog50001 3 жыл бұрын

Thank you, I appreciate the comment!

@quintingooing5495 3 жыл бұрын

This video was the single best KZfaq tutorial I’ve ever seen

@BigDog50001 3 жыл бұрын

I appreciate that, thanks!

@lloyd-qt1mg 4 жыл бұрын

The BEST use of 45 minutes of my life . WOW .... Mr. Big Dog , I'm 'blown away' by your super clear concise explanation! I'm a fan for life...

@BigDog50001 4 жыл бұрын

I appreciate the comment, thank you!

@lloyd-qt1mg 4 жыл бұрын

@@BigDog50001 My pleasure. Can't go far wrong with an Autel AL319, as a DIY'er!

@thomasderrico1751 3 жыл бұрын

As a new viewer to your videos I have to say, as a shade tree mechanic for 60 yrs and raked them damm leaves, I would like to thank you for the best troubleshooting video on the YT. Clear info with the related factors that most other guys and gals leave out, followed through and then checked the results. Thank you brother Excellent

@BigDog50001 3 жыл бұрын

I appreciate the comment, thank you!

@drabusharr Жыл бұрын

Superb - watched so many error code videos and THIS IS IT for the P0171 code (and so much more) You have provided exceptional information and methodical trouble shooting that is completely absent in most of todays garages and most certainly a dealers shop. Thank you for making this!

@joeabs4844 5 жыл бұрын

Great diagnostics and explanation Sir. Your the best in troubleshooting issues here in KZfaq! Keep it up!

@BigDog50001 5 жыл бұрын

Thank you, I appreciate the comment!

@fernandorios8499 3 жыл бұрын

Jesus I’m impressed what a good quality video! I’ve never been so immersed with information! So detailed and specific you can tell he was born to be a great mechanic!

@BigDog50001 3 жыл бұрын

Wow, thank you!

@stealthg35infiniti94 2 жыл бұрын

Thank you very much for helping fix my car. First it started with a P0420 Catalytic efficiency code. Then graduated to a P0171 lean code. Your method of explaining Fuel Trims issues and MAF Sensor testing was the Key to determining a vacuum leak. Then I looked at all hoses and used Brake Cleaner still couldn't find the leak. Finally after a quick prayer, I remembered, don't forget the brake Booster and PVC valve. Sure enough, I pinched the PVC hose to the intake manifold and the short trim fuel went from Maximum to Zero in bank 2. Bank 1 went from Maximum to about 3. Tomorrow I'm installing a new PVC valve.

@BigDog50001 2 жыл бұрын

👍

@JonathanLHaasw Жыл бұрын

Thank you for making it clear how to understand short and long term fuel trim!! I have watched a lot of videos and friends trying to explain this. NOW it’s very clear!! Can’t thank you enough.

@sjp3042 4 жыл бұрын

Thank you for being so thorough and sharing your knowledge. You are definitely installing a lot of confidence in us weekend mechanics that like to work on our own cars!

@BigDog50001 4 жыл бұрын

👍

@ianmega9550 4 жыл бұрын

You have an incredible body of knowledge in your head... just listening I learned a lot, but I sure have a lot more to learn! Really excellent job!

@BigDog50001 4 жыл бұрын

Thank you, I appreciate the comment!

@matthewmase3549 3 жыл бұрын

this was an awesome video. im a diesel mechanic and couldnt quite understand the percentages on my scan tool when hooked up to something. thank you for your time and this video taught me a lot and is sending me in the right direction for the future.

@garyzuckerman768 2 жыл бұрын

Mr Big Dog 50001 you sir are an EXCELLENT Teacher. You provide a clear pathway for understanding how to solve at least this diagnostic issue. I know you would take the same effort and then provide very clear communication for any other issue you were looking at and then teaching other about... super job!

@BigDog50001 2 жыл бұрын

Thank you, I appreciate the comment!

@nfarnell1 3 жыл бұрын

Had this problem with my 3.0 duratec, and using my 319l, went through everything and concluded the MAS was my problem. Installed a new one and both fuel trims came down, after about 30 miles both were at zero with a little up and down. The engine was clearly running better, thanks for taking the time to share your knowledge.

@BigDog50001 3 жыл бұрын

👍

@msb919 3 жыл бұрын

This was very educating and the best I have seen on KZfaq! Thanks alot!

@rafaelmeneses5066 Жыл бұрын

By far the best video that walks through an actual problem while explaining the prices of fuel trims. I have a very similar problem which I feel confident that I can narrow down more quickly with your explanations throughout the video. Thanks a bunch.

@GorillaCookies 4 жыл бұрын

This was the best tutorial Ive ever seen on KZfaq. I shows the functionality and correct use of the OBD 2 scan tool. And the way it can be used to eliminate as well as nominate possible causes of error code alerts . Both by monitoring of specific parts through real time performance readings of sensors and overall understanding of each reading and what each one means

@BigDog50001 4 жыл бұрын

👍

@dragosb2165 3 жыл бұрын

This is the most comprehensive video I have seen so far. Thank you.

@BigDog50001 3 жыл бұрын

Wow, thanks!

@martinguitarhd28 5 жыл бұрын

Wow what an excellent explanation on a lean condition.every thing you did and said was so easily understood .Loved the way you went through each detail and use of the vacuume gauge in trouble shooting.Thank you so much for your time and explanation .Really appreciated.

@BigDog50001 5 жыл бұрын

Glad you appreciated the work, thanks for the comment!

@_cici.ashley__ 3 жыл бұрын

You're one of very few YTers on here who explain your diagnostic so thoroughly. Between you & Eric the Car guy, I'm at great ease with doing my own diagnostics instead of spending $100's at the shop just for the diagnostic and I'm doing everything in my power to avoid going to an Audi service center, because I laughed at how much they would charge. I've been maintaining my vehicles all on my own and my '97 Toyota Camry just hit 355k running like a champ (best car ever to own), but I'm in a new ball game with my Audi. I've been trying to pinpoint my lean system for 3 months now and every time I correct the issue, days/weeks later the CEL comes back on. I have a 2002 Audi A4 Quattro 1.8T, and had a rich system with the code p1136. Was able to correct the code because I was running 15 lbs lower in pressure which is a sign of the filter housing/regulator. (BTW Audi/VW probably best to replace those every 10k-20k even though they currently don't have regular service intervals on the fuel pump regulator/filter housing which is 1 unit in all) I should have figured that was my cause since the fuel pump was recently replaced and the vehicle is now at 171k (recently purchased😡). 2 weeks go by and now my system is running lean with the code p0171 and I replaced the MAF sensor (with the fuel pump). I'll have to go back and check my hoses because G.E. is known for having low quality hoses. Thank you for showing us in detail with your scanner. I have an obdII at my job and I'll have to take a look on my lunch and figure out where this leak is coming from. Thank you again!

@BigDog50001 3 жыл бұрын

I appreciate the comment, thanks!

@yasharpartovi5422 Жыл бұрын

That’s why this video got over 2M view! Mannnn, best explanation I’ve ever seen in my life. technical, precise and practical. I didn’t feel like I’m watching this video for 46 minutes lol. Thank you so much for the video, well done. I think you deserve more. Again thank you for the video.

@evan937 5 жыл бұрын

My 2000 Corolla had a p0171 for years. I tried replacing the o2 sensors, cleaning the maf and throttle body, gas cap, pcv valve, even checked for vacuum leaks. Finally it went away for good once I replaced the rusted out fuel filler neck. This specific code is a tough one to figure out usually. I love my old Toyota. She has 225,000 km and still runs strong. Sadly I live in Ontario so the Rust is eating her alive.

@BigDog50001 5 жыл бұрын

Thanks for the input!

@justasmarkevicius2568 4 жыл бұрын

I think its the best and most detailed diagnostics on this particular problem. Good job sir !

@BigDog50001 4 жыл бұрын

Thank you!

@drjoeset 2 жыл бұрын

WOW ..... It would have never crossed my mind that the brake booster would have gone bad .... Thank you for the knowledge you bring to the table...

@collieryoung686 3 жыл бұрын

This video is by far the best diagnostic representation on the internet!! Thank you for the details!!

@BigDog50001 3 жыл бұрын

Thanks, I appreciate the comment!

@observer-3861 3 жыл бұрын

What a great presentation! Thank you so much for spending your time to explain the source of the problem.

@BigDog50001 3 жыл бұрын

Thank you, I appreciate the comment!

@patrickthomas6170 2 жыл бұрын

Wow,! As a nonprofessional mechanic and having watched 100s of car videos , you have made clear so many things that I didn’t really understand. Thank you for such a perfect delivery of this content for a regular guy just trying to fix his own crap and save money.

@BigDog50001 2 жыл бұрын

Glad it was helpful, thanks for watching!

@charlieparson5176 4 жыл бұрын

You've explained this better than anyone I've ever listened to on the internet. Great video 👍!

@BigDog50001 4 жыл бұрын

I appreciate the comment, thank you!

@WmTyndale 2 жыл бұрын

Going through with Scan Tool and discussion is fantastic. Eliminating possibilities and sharing experience is a winner. You communicate in a very actionable way! THE Best!

@BigDog50001 2 жыл бұрын

Thanks for the comment 👍!

@rockfangd 4 жыл бұрын

I Cannot thank you enough for posting this video. It is the best informative video I have seen for proper diagnostics of the P0171. I have no idea why someone would dislike this. Thank you for taking the time to educate.

@BigDog50001 4 жыл бұрын

Thank you, I appreciate the comment!

@yvonnadeau2331 5 жыл бұрын

I've watch many online auto repair clips and by far yours is the best and deserve my subscription. I have been waiting for you sir. Can't wait for what's next. Thank You

@BigDog50001 5 жыл бұрын

Thanks for the comment, I appreciate it!

@RK-fp7ob 3 жыл бұрын

one of the best explanations of fuel trim and diagnostics on youtube !!!

@lexathelexus109 8 ай бұрын

this is single-handedly the greatest diag video i’ve ever watched on youtube, i’ve never learned this much from a video like this before

@Zoomydoomy 3 жыл бұрын

I'm glad I watched this entire video instead of clicking away early on. I learned so much.

@BigDog50001 3 жыл бұрын

Glad it helped, thanks for the comment!

@elfocker 3 жыл бұрын

Me too 🤣 awesome work 👍

@Longtrailside 5 жыл бұрын

Very well done. I appreciate all the hard work that you put into this, it was very educational.

@BigDog50001 5 жыл бұрын

Thank you, I appreciate the comment!

@glennbruner7504 Ай бұрын

This is a very well done video. He shows precisely his process of checking out the fuel trim system and looking at the O2 sensor reading along with the Mass Air Flow sensor. Uses logical interpretation of readings to do an effective job of isolating the parts of the system to narrow down the repair focus. He really makes understanding the closed loop system relatively easy. And shows what multiple problems together do to the feedback look of the fuel system. Best video I have found to really understand and troubleshoot a P0171 issue on my Toyota!! Thank you!!

@tmph1814 2 жыл бұрын

This is the most educational and useful diagnosis I've encountered to use to fix my 99 Lexus RX300 with a dozen of CEL codes. Thank you very much BigDog!

@BigDog50001 2 жыл бұрын

I appreciate the comment, thanks!

@davidholzbaugh652 2 жыл бұрын

Great info ! Your a great teacher!!! We need more real people like you in this world !! God bless you !!!🤙

@BigDog50001 2 жыл бұрын

I appreciate the comment, thank you!

@petmim3583 3 жыл бұрын

The best video i ever watched!! Totally understandable and as *evandrewmartinez1* said "This video made me feel like I already fixed my po171 and I haven't even went outside yet"!!!!

@BigDog50001 3 жыл бұрын

lol, thanks for the comment!

@BigDog50001 4 жыл бұрын

Be sure to subscribe for more tool and car repair videos! kzfaq.info The Big Dog 50001 Automotive Channel Store can be found here: (This channel earns a small commission for purchases made through these links - at no cost to you) www.amazon.com/shop/bigdog50001automotive twitter.com/BigDog50001 instagram.com/bigdog50001/ Want a free Big Dog50001 sticker? Send an email to bigdog50001@gmail.com requesting a sticker. Sorry, no international addresses.

@sean_heisler 3 жыл бұрын

Boom! This video helped me find the issue. I recently replaced the thermostat on my 2014 Chevy Cruze and it was within a day or two after that I started getting this code. I had to dissemble the PCV hose near the thermostat for better access and I must have cracked the aging plastic air hose! I felt the crack upon inspecting the hoses as you suggested. Taped it up for now and waiting for a replacement hose from Amazon now. Thank so much!!

@cavikid5339 5 жыл бұрын

Amazing video. Helped so much. My cavalier is doing the exact same thing. Changed my fuel filter and it went away. Plugged filter so it was throwing way more fuel to compensate for it.

@BigDog50001 5 жыл бұрын

Thank you for the comment, glad you got yours fixed!

@jimintaos 5 жыл бұрын

Thank you, I really found this helpful. I've been working on my 2001 4 Runner and replaced plug wires and plugs, cleaned and rebuilt all of the injectors, eliminated all of the vacuum leaks and replaced a defective fuel pressure regulator and then, yesterday, I bit the bullet and replaced the fuel pump because all of my tests seemed to indicate a fuel pump issue. Still, the same problem. Idles like a champ, maybe a slight miss, but the moment the throttle opens up it bogs down. After watching your video I decided to go back to square one and do what I had done on day one and start with the MAF and work my way back. This time I happened to look into the MAF and saw that the sensor deep down in the guts of it was all crudded up. I flushed it with MAF cleaner, let it dry, put it back, started the engine, blipped the throttle and the problem was solved. No more P0300 and no P0171. Runs like it is supposed to. Only one thing left-the oil change. So, thanks again for the pointers and the process and above and beyond all of that-explaining in a clear, straight forward way without even the barest hint of over amped ego or sarcasm. Consider me subscribed to your channel and un subbed from that other guy. Thanks.

@BigDog50001 5 жыл бұрын

Thanks for the comment and welcome!

@jerryhanson3903 4 жыл бұрын

I have the same problem with a 3.8 GM engine. I changed the fuel pump, mass air flow sensor, fuel pressure regulator, vacuum hoses and even the fuel filter same problem. No shop I go to can figure it out.

@tedcarlton9905 Жыл бұрын

this guy really understands how it works and how to use the tools plus he explains things in clear way

@BigDog50001 Жыл бұрын

I appreciate the comment, thanks!

@justinmiller3114 4 ай бұрын

I wanted to leave a comment saying "thank you" for making this video available on youtube. Recently experienced p0171 on my dodge magnum and your information helped my pinpoint my issue with ease. Thank you again from Texas.

@BigDog50001 4 ай бұрын

Glad the video helped, thanks for the comment!

@robertbcurry2698 2 жыл бұрын

This was great! Very informative and helpful. Thank you for the time you have put into this and the information you shared. I learned quite a bit, just a shame I don't have all those fancy tools you do ;)

@eseybold1 5 жыл бұрын

Absolutely top quality video - easy to follow and clear - great job !

@BigDog50001 5 жыл бұрын

Thanks!

@2002boriszhang 3 жыл бұрын

I want to thank you for posting this very detailed diagnosis video. I have a 06 Accord with a pending CEL code P0171. Fuel trim was at +25% at warm idle. I followed your procedure, and found out that my air intake tube had 2 huge cracks. After installing the new tube, fuel trim wasn’t changed. I moved on to see the live data and found out my MAF sensor was under reporting. Since the Tacoma in your video and my Accord all have the same size engine, 2.4L, I found my MAF was under reporting even worse than the Tacoma in this video. I ordered a new MAF sensor and now the problem is solved! Thank you again sir as p0171 can be very tricky and costly to diagnose. Your video is extremely helpful and saved me a lot of money. As a DIYer myself, these videos really help!

@BigDog50001 3 жыл бұрын

👍

@lloyd-qt1mg 4 жыл бұрын

Hi Mr. Big Dog 50001, You really do explain using the AL 319 ( which I'm still learning how to use), in this video extremely well! I've just bought a 'lemon' of a V6 2003 Jeep (Cherokee in Australia & Liberty in USA), with 125,000 miles on the clock. It's thrown up the 'Check Engine Light" ( not flashing ...yet!) on the dash. I used my UL319 OBD II Code Reader, which spewed out following DTCs: (i) P1391 - $10 Generic - Camshaft Position Sensor . A circuit Bank1 or Singl (ii) P0340 - $10, Pending, Chrysler, Interim loss of CMP or CKP. As a DIY 'ignoramus', with a multimeter as my 'only' other diagnostic tool, I'm floundering all over the 'Net' for help, ... as I'm in a panic that 'Big Dollars' might be the only solution to turning this 'lemon' into a sweet orange! So far all paths are pointing to the following troublesome possibilities: (a) Cam & Crank out of sync. because of Timing Chain elongation/stretch, (b) Sensor/s have self-destructed. (c) Fault in the wiring harness. (d) The notched disc that generates the 'Hall effect' wave patterns has broken in the engine. (Typical unit used in Chrysler products) Possible action going forward: (i) Check: (i) Power line, (ii) Ground line, and (iii) Signal line at each Sensor, for 'A" OK - before running out and buying replacements. If you can offer any advice towards making my Cherokee a ' sweet orange' ... I'll be most grateful! Perhaps a link or two that 'homes' into my 'dilemma'. Thanks again for your super instructional video pertaining to 'P Code', DTCs. Best regards, Lloyd.4560@gmail.com Queensland, Australia.

@jamesoberg8809 4 жыл бұрын

Amazing thorough explanation of diagnosing the problem and a huge help understanding how to read my Autel Scanner! Thank you so much!

@BigDog50001 4 жыл бұрын

Glad it helped, thanks for the comment!

@billyyoder8171 5 жыл бұрын

Thank you Dave. Text book explanation. Good job. I appreciate your videos. Have a blessed and safe week.

@BigDog50001 5 жыл бұрын

Thanks, I appreciate the comment!

@willefixit 5 жыл бұрын

@@BigDog50001 better than text book!!

@guilhermeg345 Ай бұрын

The best explanation yet, the fuel trims on my car are really high like 45% on short and 50% on long but no fault codes. This will come in handy.

@DJ-yl5xp 4 жыл бұрын

This video was as clear as it could ever be. Followed closely, concluded that it had to be a vacuum leak to both cylinders (p071 and p074 on 03 avalon). After spraying carb cleaner to no avail ,rubbed my fingers like shown in video along bottom of vacuum hoses and found a crack below hose going to brake booster. Love !!! this dude. 5 stars

@BigDog50001 4 жыл бұрын

👍

@patriot2164 4 жыл бұрын

Sir , 1st Time Viewing your channel, I love the explanations , I watch numerous automotive channels and alot of those channels seem to think everyone has the same knowledge levels , I love the background information to get everyone on the same page ! Thanks

@BigDog50001 4 жыл бұрын

Glad it helped, thanks for the comment!

@patriciomunoz2830 4 жыл бұрын

Hey good video, it's nice to see troubleshooting in 90's cars, every other channel are fixing newer cars Subscribed

@BigDog50001 4 жыл бұрын

Welcome and thanks for the comment!

@user-sc8ev5sr1o 6 ай бұрын

I really like your attention to detail searching and finding the exact problem I just love it

@11b248h 4 жыл бұрын

Thanks a ton Big Dog. I've been hunting down an issue with our 08 H3 Alpha. Keep getting P0171/P0174 along with other DTC codes. Ive replaced all 4 cats, all 4 O2 sensors, complete tune up, Cranks position sensor, MAF sensor and others. 8 months now chasing this issue and still no luck in identifying it. But your vid definitely gives me a better view as to how to better diagnose this issue. Long story short, Thanks for taking the time at explaining the different values (MAF, LT/ST Fuel Trims and such)

@BigDog50001 4 жыл бұрын

Thanks for taking the time to leave this comment, I appreciate it!

@jeremyharwood5116 4 жыл бұрын

Wow! Such an informative video. Thank you for taking your time to make this video, it doesn't get any better than this! Subscribed!

@BigDog50001 4 жыл бұрын

I appreciate the comment, thanks!

@bwwilson1765 4 жыл бұрын

Fantastic video! What a great refresher for my very old diagnostic skills. I was looking for just this kind of in depth explanation, as I am helping my son diagnose his dual 0171 &0174 codes on his "new" '02 Ranger with a 4.0L. Perfect primer for the work! Thank you for sharing your time and diagnostic approach in a clear and concise way. BTW, the link for the Amazon link for the MS906BT goes to the MV108 Inspection scope, not the Scan tool, FYI.

@BigDog50001 4 жыл бұрын

I appreciate the comment and the heads up on the wrong link, thanks!

@rytoniowendolini2793 8 ай бұрын

I have the exact same codes together right now as your son, what ended up being the problem?

@bwwilson1765 8 ай бұрын

@@rytoniowendolini2793 The fuel pump/pressure was one issue. I think there was an issue with one of the O2 sensors as well I think.

@nasirjan6903 Жыл бұрын

This is the best mechanic I have ever seen. You are a scientific mechanic. I wish you were close so that I could bring my dodge avenger to you. It has similar issues but no mechanic can make the right diagnosis. They have charged me more than 10 times but still my car dies randomly while driving.

@pfsantos007 4 жыл бұрын

Best video on the subject of vacuum leaks. Excellent explanation and very detailed going through the different symptoms and how the readings change.

@BigDog50001 4 жыл бұрын

I appreciate the comment, thanks!

@billdavison2303 5 жыл бұрын

Great video for diagnosis of a P0171! Thank you!

@BigDog50001 5 жыл бұрын

Thanks!

@wyattoneable 5 жыл бұрын

I have that AL319 and it's a pretty handy tool for a quick look. You did a nice job explaining the PID's and OBD II protocols. I won't comment on what the issues were so I don't ruin it for others, but yeah, nice diagnostics to figure it out.

@BigDog50001 5 жыл бұрын

For not much money it is a good little tool, that is why I showed it in the video. Thanks Wyatt, I appreciate the comment!

@JohnOldman-we4pe 10 ай бұрын

That's the bestest about P0171 that I have ever seen on YT and others. Well done bro, preciate your awesome work.

@toneytoney822 3 жыл бұрын

I didn't watch video to the end initially, I had to give you a 2 thumbs up for giving that fly warning! You really broke it down that a dummy would understand. Once again great job

@BigDog50001 3 жыл бұрын

lol, thanks for the comment!

@TheMezzy712 4 жыл бұрын

Hi, I love your videos and first and foremost I wanted to say a massive thank you for educating the public with your unique skills and techniques. I have a problem that been bugging me and would really love to run it past you to see if I'm on the right track.I have a Suzuki Swift EZ 1.5litre petrol. The car starts cold idling at 1000rpm. As the temp increases, this gradually rised to 1900rpm on idle at operating temp.The throttle cable idle screw is completely out to it's lowest setting with zero tension on the cable.I checked all vacuum leaks and can confirm no leaks what so ever. Closer inspection and process of elimination shows no leaks. But, when I start the air conditioner my idle will come down to 1100rpm when compressor engages. I've replaced plugs and coils, also replaced Air flow meter and automatic idle solenoid on the throttle body yet no change. On idle 1900rpm my SHRTFT is 3.9 and LONGFT is -2.3. MAFg/s 4.45 O2BISV 0.090 O2BIS2V 0.555 and FUELSYS1 is in CL closed loop. However I have a TP% reading of 14.5. Is this Throttle possition? Should this be at 0% My next guess is to replace the O2 sensor before the cat. Am I on the right track? Would love to know your view?

@UrduOfficialNovel 3 жыл бұрын

Thumbs up man, you made me feel like I'm a pro mechanic.keep it up.we need people like you to share their knowledge for good.

@BigDog50001 3 жыл бұрын

Much appreciated!

@rubenmelendrez6680 Ай бұрын

Thanks, thanks, and thanks. Almos anybody can upload a video this days, but to put the amount of effort and years of knowledge and experience compounded together!!!!!!! It deserves recognition, admiration and respect. Thank you Sr. For such a great lecture.