What Does SYSTEM LEAN Mean?

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HumbleMechanic

HumbleMechanic

8 жыл бұрын

What The Heck Is SYSTEM LEAN? No one likes when the check engine comes on in their car. One of the more common issues with check engine lights is a system lean fault P0171 is the most common fault code. This fault can be tricky to diagnose if you don't understand what system lean really means. This can be too much air, or not enough fuel at the engine. System lean is not hard to diagnose, once you understand it.
Join me today as we discuss:
~One of the most asked questions I get
~Perspeption of unmetered air/not enough fuel
~Calculation based on feedback from sensors
~How does it happen
~O2 sensor voltage
~Correction by ECM
~VCDS Reading
~VCDS Demo ~ • VCDS or Vag-Com Review...
~System Rich VS System Lean
~Diagnose system lean on my Passat ~ • Volkswagen Check Engin...
~and more
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Пікірлер: 340
@spelunkerd
@spelunkerd 7 жыл бұрын
Nice review. For those of us who don't do this every day, remembering which way the values are pointing is the first hurdle. Also it's wise to remember whether we are looking at the correction (fuel trim), or raw O2 sensor data. That's mostly a matter of understanding tools, in this case the interface program we are using. Conveniently, when looking at O2 sensor data, higher voltage means rich, and when looking at trim, higher positive numbers mean the system is adding fuel. That similar alignment makes it easier to remember. Of course on the surface it can be confusing since adding fuel is usually a response to a lean condition downstream, which may be completely corrected by the addition of extra fuel. So I see your point, look at trim first because the O2 sensor data may be obscured by correction of injector pulse width. Thanks! Your description of the most common points of failure adds practical guidance to how experienced techs solve problems.
@mikewatson2951
@mikewatson2951 8 ай бұрын
Nailed it. Been to so many mechanics, had the PCV done, injectors, EVAP, MAF....Paid thousands. Still got the fault code. Had a root round the bay today myself and found and easily found the brake valve hoses were badly cracked!! Just paid $165 bucks for replacement, can't wait to get it in and test it. The cars fuel economy has been terrible for over a year!
@dnlpark
@dnlpark 8 ай бұрын
please let us know if it worked!
@Pali4life2
@Pali4life2 8 жыл бұрын
Great video Charles. I remember having a big problem with this on my old 1.8t AWP engine. I replaced the diverter valve because it went bad and when reinstalling the hose on the left side of the diverter valve it was in a slightly different position than it was initially. This caused it to touch what looked to be a metal fuel line behind it. From the heat of the fuel line the rubber hose split open causing a huge leak. I battles this problem for a LONG time and the car always ran in limp mode. Just advice to everyone when working in your car, pay attention to all the details!! Listen to Charles! If i just did a more thorough inspection it would have saved me a lot of time and money. Lesson learned I guess.
@ne2i
@ne2i 8 жыл бұрын
just had this issue, my PCV system had big cracks and vacuum leaks. don't forget to look there also!
@js50025
@js50025 4 жыл бұрын
I don’t know much about cars but this video has helped me tremendously in understanding what’s wrong with my car. Thank you
@dtrimm1
@dtrimm1 3 жыл бұрын
Visual inspection… yep, I found the problem and fixed it! Thanks very much Charles for another super-informative video. Keep ‘em coming!
@algardner2391
@algardner2391 Жыл бұрын
I didn't get that opportunity for visual. I had to feel around the back of the rear most intake hose into the bank 1 throttle body. Rib Rib Gaping hole Rib 😂
@caltravels9454
@caltravels9454 7 жыл бұрын
Hey HumbleMechanic, I really enjoy this community of channels, I mean You, EricTCG, ScottyK, ChrisFix, and others, this community has really served me well and saved me 1000's of dollars, i'm getting a new clutch atm, paying 1400 for a shop to do it, a HD clutch in my 2002 3.4L V6 Hilux which to me is reasonable, I cannot do that with my tool kit, just before having to surrender my car to the shop, for the first time ever in 5 years it would not start, I have a new battery, it cranked strongly half a dozen times, cranking it for a handful of seconds each time, it did fire up eventually after letting it rest between each attempt and it was rich, tested all the vacuum lines, they were fine, pulled out my MAF sensor, it was dirty, already had the cleaner and turned out that was the problem, MAF was filthy, easy 20 (for the can Co2) fix that, I can only guess what a shop would charge extra. I asked Eric to recommend more Toyota designated Channels and he did name ScottyK, so I would like to ask you the same Q.
@HumbleMechanic
@HumbleMechanic 7 жыл бұрын
Thanks for the kind words to all of us. It really means a lot. This type of thing aint easy, so it's always so warming to hear. I don't really know many Toyota sites. I wish I did LOL, that is like a foreign language to me HAHA
@RPHPros
@RPHPros 5 жыл бұрын
Thank you HumbleMechanic for making this video and your clear explanation. I found my wife's problem through your basic explanation. the last time the Subaru was in the dealership they removed a clamp and never replaced it leaving the air intake the fall off which is what caused the check engine light. I never would have thought to do a visual inspection had I not watched your video. Thank you.
@brakedd
@brakedd 8 жыл бұрын
This is an awesome video Charles. I don't know how many times I've seen people throw o2 sensors at a vehicle with P0171 and 174 without any diag.
@BrianBroughten
@BrianBroughten Ай бұрын
Raises hand. I threw o2 at after a $500 valve cover replacement by a "professional shop" and a MAF and still coding. I have an aftermarket INjen cold air intake and Im blaming that because the car run better with it, than without it and it snorts. 2.5L 06 Jetta
@craigdarpino6072
@craigdarpino6072 6 жыл бұрын
This video is so perfect. You made me finally understand how all of this works. Great job! My brain always went to vacuum leak in a system lean condition. This gives me much more to think about. Thank you!
@made2blaze
@made2blaze 8 жыл бұрын
Such a great video. You explain things so well! I have one of these in the shop right now and I can't wait to get back tomorrow and figure it out.You really make me want to continue my career as a technician.
@davejohnson1819
@davejohnson1819 4 жыл бұрын
I had this on my Toyota 3.4L V6, it was the Mass Air Flow Sensor, cleaning helped, replacing fixed it.
@HumbleMechanic
@HumbleMechanic 4 жыл бұрын
NCIE
@SleeplessinOC
@SleeplessinOC 4 жыл бұрын
How long after you cleaned it did you just decide to replace it ?
@nivag.2104
@nivag.2104 5 жыл бұрын
Really feel like I can be a mechanic after watching this 😶😳🥰
@DougHinVA
@DougHinVA 4 жыл бұрын
no you can't.... what you 'feel' is imagination and very different from actually doing work with tools correctly.
@Aceboogz100
@Aceboogz100 4 жыл бұрын
Doug H. in VA shut up Doug 🙄
@Hoodie2103
@Hoodie2103 4 жыл бұрын
Doug H. in VA yeah, shut up Doug. 😂
@iamSOSOVIcious
@iamSOSOVIcious 3 жыл бұрын
@@DougHinVA no 8
@cloutgangster
@cloutgangster 11 ай бұрын
You belong in the kitchen!
@rhkips
@rhkips 8 жыл бұрын
"System Lean" means the car is on it's side. Check for overweight driver or passenger, angry mob, earthquake-related fissure, unusual changes in gravity, or acts of god. Not to be confused with "System Rich," which is when you suddenly find yourself driving a Bentley. :D Another great video! Love the visual aid. Who ever thought a giant tube could teach so much?
@bendude6748
@bendude6748 2 жыл бұрын
I just had this happen on a car I bought, turns out the previous owner must have had an intake kit on the car and then shoved the old standard intake on before I got it and forgot to mention he had somehow sliced a big gash in the underside of the intake pipe causing a massive vacuum leak that I couldn’t see until I removed it.
@rdaugherty52
@rdaugherty52 4 жыл бұрын
I have a Chevy Silverado with 4.3 liter engine started missing one night check engine lite came on system lean bank 1 short term 55 long term 25 no vacuum leaks. Suspect a bad 02 sensor before cat and looks like that's what your saying in video. Thanks for showing
@2015_Rubicnn
@2015_Rubicnn 5 жыл бұрын
You aren't going to have a vacuum leak before the throttle plate. You will however have an air metering error comparing the intake mass air vs O2 reading. The idle air control valve could cause this issue as well being it's a controlled vacuum leak.
@adamdlugose
@adamdlugose 8 жыл бұрын
I have been dealing with this code for about a month now on my 99 yukon. I have checked and cleaned everything i could. Just found the problem yesterday and it was that the exhaust flange gasket deteriorated away and it is located right before the o2 sensor.
@kenmh7357
@kenmh7357 4 жыл бұрын
Getting a P12A2 at the same time. Cold start misfires first (most likely carbon), warm engine, clear codes then get P0171 and sometimes P12A2. Fuel filter has not been changed for a while
@naturallyaspirated7829
@naturallyaspirated7829 3 жыл бұрын
You're a great educator my friend Clear and concise Thank you
@AwayResortHuaHin
@AwayResortHuaHin 8 жыл бұрын
That Integrated Engineering intake looks awesome!!
@ImAzraa
@ImAzraa 8 жыл бұрын
a/b = Q Ideally, Q should have a value 'k', which is a constant for the ideal ratio for your car, but Q represents the real result obtained from conditions a and b. How do you keep Q=k when a and b are changing every few ms? Well if b increases means we divide by a larger number, decreasing our result (Q < k) but we dont want that. We want Q to remain equal to k. In that case, you can increase the value 'a' to compensate the change introduced by increased 'b' On the contrary, if b decreases, we divide by a smaller number, increasing our result (Q > k) For this case, you can decrease the value 'a' to compensate Simple math to understand the fuel/oxygen ratio explanation. Both scenarios have variable values that produce a ratio (Q) which we want to be constant at a value 'k'. In order for the engine to operate at top performance, you have to account for the changing values a and b (fuel and oxygen) at every detonation, on every cylinder.
@dvcavall
@dvcavall 7 жыл бұрын
Great video. I'm afraid I fall into the diy camp of changing a long list of parts on my 2008 Audi a4 2.0t fsi, and not fixing the problem. I also had it at a local shop that said they did a fuel pressure test and a smoke test, and couldn't find the problem. Not an Audi specialist. Wonder if I need to give up and pay the dealer the 169.00 to diagnose the problem. I changed the MAF, purge valve, checked the hpfp and changed the cam follower even though the one in there looked fine. Changed plugs, Mercedes fuel system cleaner, fuel filter, pcv crack case thing, pcv hoses. After changing the pcv hoses it got better, but still comes back after a long drive (over an hour) and only shows at idle. Lumpy, almost dies but doesn't. Otherwise runs great off idle. I am stumped. Only throws P0171, no other code.
@karlhendricks8864
@karlhendricks8864 Жыл бұрын
Hi David i done the same as you 2007 Audi A3 1.8T , my engine runs fine , then one day i notice a check engine light , hooked up the scan tool and it was a P0171 , first thing i changed was PVC valve , MAF sensor , air filter , fuel filter , i cleared the code every single time but comes back , buy this time im getting confused , take it to garage they hook up smoke machine they said it was your rear main seal and showed me where the smoke was coming out , so i thought i would try some Rislone rear main seal repair oil and it has stop the slow oil leak i had but the engine light still comes on??? ,
@dvcavall
@dvcavall Жыл бұрын
@@karlhendricks8864 Thanks for the comment Karl. It's been fixed for several years now thankfully. The problem was what I will call a breather/vent hose that I believe goes between the crankcase and manifold. On the 2008 2.0, it is a silver metal formed hose toward the front passenger side on the engine. A German mechanic told my mechanic to take it off and blow through it from both ends. Apparently there is a valve in the middle of the hose you can't see that should stop air flowing in one direction. Since the mechanic could blow in both directions it acted like a vacuum leak which usually is far worse at idle since there is little fuel being demanded. A new hose fixed it. Not sure if that crank case vent hose is on the 1.8 or not.
@karlhendricks8864
@karlhendricks8864 Жыл бұрын
Wow that's good you have it sorted out , and it was just one breather hose ! Maybe I will check mine
@daddychitown
@daddychitown 5 жыл бұрын
Easy to understand that is a gas guzzler nightmare! Great video 👍
@SouthMainAuto
@SouthMainAuto 8 жыл бұрын
Hey Charles, good vid touching a bit on the topic of lean (P0171, P0174) codes focusing on un-metered air and faulty O2's. I Ever give any thought to skewed MAF readings i.e. dirty/ faulty MAF or perhaps issues in the VVT causing lean trouble codes, engine mechanical timing i.e. incorrectly installed timing belt on one cam, sheered key ways etc. or perhaps engine mechanical condition i.e. valve lash etc.? Just curious your thoughts on that and also any thoughts on chasing down lean codes on speed density engines as opposed to MAF engines? Also may keep in mind to that an ignition miss-fire will cause a lean code :) No combustion and all it does is pump air right? HC's can not be read by the O2.
@HumbleMechanic
@HumbleMechanic 8 жыл бұрын
+South Main Auto Repair I have only ran into maybe 2 sys lean caused by mechanical issues. It's sure possible, but not common(in VW land anyway). I agree that there are more issues with system lean. But I think that will be System Lean 202 class. Haha. For the first run of these videos I want to keep it simple to get people mind moving in the right direction. Mostly so thy stop just throwing O2 sensors in.
@SouthMainAuto
@SouthMainAuto 8 жыл бұрын
Wait you mean if I get a lean code I shouldn't just change the AFR's and a fuel pump first ;) Haha Can't wait for Lean Codes 202 :) I have had a few neat case studies on mechanical issues setting lean codes... they can mop the floor with ya if you are not careful! Keep up the good work!
@chadcohoon8867
@chadcohoon8867 8 жыл бұрын
+South Main Auto Repair ERIK O FOR PREZZ LOL
@aldoramirez6152
@aldoramirez6152 5 жыл бұрын
South Main Auto Repair Saturno Outlook
@aldoramirez6152
@aldoramirez6152 5 жыл бұрын
Saturno Outlook 2008
@juliogarcia5304
@juliogarcia5304 4 жыл бұрын
P0171 code, my car when it's cold will start right away but if I let it cold for 15 min wont start or will have a very hard time to start. I had spark plugs oil on them, I change the spark plugs and valve cover gasket, fuel filter, the mass air sensor.
@davidmiller2257
@davidmiller2257 7 жыл бұрын
I recently replaced my 02s. Forgot to disconnect the ground from my battery caused a short. Obviously... my Taurus blew the fuse under the hood. Number 28. Made the rookie mistake of climbing over the engine and working the intake loose. Long story short check your. vacs your codes and double check your own work.
@_________________7791
@_________________7791 6 жыл бұрын
What the hell? Why would you disconnect the battery to disconnect a o2 sensor? Just keep your car key in your pocket thats more than enough to disconnect the o2 sensor without going anything wrong
@praneethudayanga1110
@praneethudayanga1110 8 жыл бұрын
Hey Charls.. keep up the good work. i watch your videos probably 3-4 times to make sure i get everything you say. because there are so much information to absorb as a student mechanic. thanks for all the information (Y) good luck
@HumbleMechanic
@HumbleMechanic 8 жыл бұрын
Thanks so much for the kind words. Glad to be able to help.
@stanleymakafui
@stanleymakafui 9 ай бұрын
This man is so intelligent
@91rss
@91rss 10 ай бұрын
friend just had the issue turns out Brake booster was rusted and allowing air in, Pinching the vacuum line to the booster proved the issue at the booster was the cause
@artdogg50
@artdogg50 4 жыл бұрын
So what are the costs differences to get this fixed? I'm hearing anywhere from about $50-$100 up to $1000.
@HumbleMechanic
@HumbleMechanic 4 жыл бұрын
Yes. It depends on the issue. There are tons of things that can cause a system lean
@suggesttwo
@suggesttwo 7 жыл бұрын
Vacuum leaks look for loose and add tape to the male end or cut off the end of the vacuum line that has stretched or replacing the vacuum line.
@jhfjhfkf
@jhfjhfkf 2 жыл бұрын
Excellent review, very informative and detailed. Great display of knowledge.
@haywire17
@haywire17 6 жыл бұрын
So on an MK4 (2001) Jetta (1.8T AWW), how many drive cycles will it take the CEL to reset on its own (After a fix)? I did the stupid thing when I first bought this car (because I wasn't sure I was going to keep the car...) - I bought a $19.00 MAF from ebay. It only lasted 8 months, and then began (even after cleaning) under-reporting airflow, causing an intermittent P0171 code every time the LTFT hit 20% (Under ALL engine loads). Today, I installed a Bosch MAF, and cracked a smile when it entered closed loop, and STFT immediately pegged at -20% while the +20% LTFT began dropping. 3 drive cycles later, I have less than 8% LTFT and still have some negative STFT, which is still working on bringing that LT number down. I'm confident the problem is fixed, but wondered how long it will take the ECU to figure out that the problem is fixed and clear the CEL. Figured I'd ask a VW man :-)
@senpai_ttc380
@senpai_ttc380 4 жыл бұрын
P0171 I would like to add something to this that i just experienced. I have the n249 delete sia delet etc. And this code gave me the run around for weeks. Smoke test leak test everything. Well because of those deletes i have bypassed my diverter vacuum line to the throttle body next to bank 1. Well the vacuum side of the diverter when out and was allowing boost pressure to enter after the trottle body right into bank 1. Long story short. New diverter valve fixed it. Sad part about this is a smoke test wont show it
@tedbear631
@tedbear631 7 жыл бұрын
very cool charles TIL thanks for the awesome vods
@imatter4619
@imatter4619 3 жыл бұрын
Great video, I have the P0171 code on my 97 Oldsmobile and on top of that the car doesn't start half the time. I changed the fuel filter like 10k miles ago and the car has 120k miles. I'm thinking since the car doesn't start half the time it might be the Fuel pump. Any Idea if it can be something else. Thanks
@_________________7791
@_________________7791 6 жыл бұрын
i like this guy, he’s very detailed and knowing what he is saying.
@HumbleMechanic
@HumbleMechanic 6 жыл бұрын
Thank you
@realgamer1789
@realgamer1789 6 жыл бұрын
bro please answer some of these questions they pertain to others as well
@HumbleMechanic
@HumbleMechanic 6 жыл бұрын
I answered that question on O2 sensors in a reply to the person that asked.
@94tonys
@94tonys 7 жыл бұрын
What would be the cause of a lean condition from using E85 in a non flex fuel vehicle. From what I've gathered for my vehicle, is that it's burning more efficiently or cleaner, or faster. Could it be that my vehicle is not pumping enough of the E85 to be efficient?
@koitorob
@koitorob 4 жыл бұрын
My old Land Rover had system a lean. I fixed it by replacing the leaf springs. It doesn't lean any more.
@HumbleMechanic
@HumbleMechanic 4 жыл бұрын
Ha Hahahhahaha. I enjoyed that more than I wanted
@jjreed1554
@jjreed1554 4 жыл бұрын
Lol
@ozzstars_cars
@ozzstars_cars 8 жыл бұрын
well said explanation on fuel trim percentages
@chiya2006
@chiya2006 Жыл бұрын
It’s been over a week now I’m having the same problem. It reads (Po171 system too lean Bank 1 ) still haven’t figured out if there’s a vacuum leak, bad O2 sensor, or bad fuel delivery!. I’m getting tired of looking for myself. The sad thing is there’s isn’t an honest mechanic where I live, they’re all crooks, thieves simply robbing us in broad daylight. And I can’t afford a new car
@MotionArtist3D
@MotionArtist3D 4 жыл бұрын
Can an OBDII diagnostic alone can determine the exact cause of 'system lean' error code? Also, if the fault is with the oxygen sensor, is it best to replace both (I know there are 4 in a normal car) one before the catalytic sensor and one after? even if the second one is not faulty? Thank you for the great informative videos. Subscribed!
@RobDeRosaActor
@RobDeRosaActor 3 жыл бұрын
Smart guy. Great details. And if I was a mechanic or Am aspiring one, I Might have understood a tiny bit of that. Nope. I watched to see of I could learn how serious this is in the short term....onto the next search result.
@HumbleMechanic
@HumbleMechanic 3 жыл бұрын
It can be minor or major. Totally depends
@johnsmith-dx8vy
@johnsmith-dx8vy 8 жыл бұрын
what if your running lean with out being on Wide open throttle? also having lean issues after rev down ..so rev it as it goes down ..runs lean
@mikeoneill7360
@mikeoneill7360 7 жыл бұрын
Excellent presentation....
@jackrios4040
@jackrios4040 6 жыл бұрын
I have a p2096 code but I only pops up when I put my tuned ecu in. Nothing is wrong with my car because my other ecu doesn't have that code when I have it in
@tommyr1341
@tommyr1341 5 жыл бұрын
Did you ever work this out going through the same thing right now
@williamrockhill8018
@williamrockhill8018 5 жыл бұрын
i replaced my o2 sensor problem i put in crocked because some striped the treads my screen on the 02 sensor screen on the end got crushed and it spines could that cause o2 sensor to fail
@jamez2u
@jamez2u 7 жыл бұрын
First I loved this video, even though I have (knock on wood) never had a P0171 fault code. I suppose I liked it so much because of the training that I had was useful in making sense of the jargon that was used in this video. I don't know what expertise level your user base has but for those who have not had training in fuel systems it may be useful to put definitions in boxes while you are explaining more complicated troubleshooting techniques when using jargon such as fuel trim pulse or width. BTW you it would be cute to get a beard and mustache for our daughter and dress her up as the HumbleMechanic for Halloween.
@seangreenplate3037
@seangreenplate3037 3 жыл бұрын
Great video! However after replacing just about every major component on my MKV R32, I still get o2 sensor faults. It’s driving me insane and my pockets are emptied out
@HumbleMechanic
@HumbleMechanic 3 жыл бұрын
Oh no! Could be a monitoring fault like a vacuum leak
@seangreenplate3037
@seangreenplate3037 3 жыл бұрын
@@HumbleMechanic replacing the thermostat took care of some of my issues. However, I’m still getting codes P2196 (too rich) and P2096 (sensor correction) for bank 1. Could the upstream o2 sensor need replaced or could it be a problem elsewhere? I know it’s hard for you to say, just trying to pick an expert’s brain!
@heshandong7083
@heshandong7083 2 жыл бұрын
Great video. I don't know who is still watching this video, I need help. I have a 2012 VW Jetta Sportwagen 2.5, and I have been battling with the code P2096 for a few months. I have replaced a ton of parts, including valve cover, plugs, air filter, MAF sensor, O2 sensors both upstream and downstream, and the code still stays. some times it goes and sometimes it comes again. checked the intake and seems fine, as it has the MAF sensor after the throttle body. I don't know if the oil leak at the vacuum pump really causes this. The oil leak at the vacuum pump is obvious and I check it regularly.. So, I am going to fix the vacuum pump oil leak first, then, if the code still remains I will check the harness under the chassis around the exhaust. I need someone who are experienced this code on this car.
@JohnnyKawasaki
@JohnnyKawasaki 2 жыл бұрын
Currently battling this pcode with a f150 eco boost 3.5 have you had any luck yet?
@heshandong7083
@heshandong7083 2 жыл бұрын
@@JohnnyKawasaki unfortunately no man. I have tried to fix the oil leak at the vacuum pump first as there are comments about fixing the oil leak first. I have tried to fix the oil leak with an RKX kit and the leak stopped. Then, the p2096 code still remains. recently I have gone to the Autozone and found it comes another code P117a which VW official site says the harness of the underneath sensor may be improperly connected, or the O2 sensor may not be properly installed. Maybe I have to go to a shop and lift it up to see if the connection, harness, or o2 sensor has problems. Another possibility is the ECM or ECU is wrong. So, still battling with this code. My car does not have any other codes.
@ItsRandomStan
@ItsRandomStan 6 жыл бұрын
You should do a episode or episodes of pro and cons of doing each mod, and when doing a certain mod, what you should do
@Showstarautoservice
@Showstarautoservice 2 жыл бұрын
I have a kia fote ex 2012 with P 2191 code what should I check
@Justinwhat1
@Justinwhat1 6 жыл бұрын
This was EXTREMELY helpful.
@Leo-yn5fx
@Leo-yn5fx 7 жыл бұрын
Cleanest mechanic on youtube for sure. Lmao almost like an infomercial for mechanic tipsz
@_________________7791
@_________________7791 6 жыл бұрын
my long term fuel trim whas 12 % the car had no fault codes, but the performance of the engine really sucked! After checking for false air and replacing all filters still the same. So at the end i replaced the front o2 sensor with a new oem one. And now the car feels like a whole new car a lott lots of power and the long term stays at 0,5 %. Never trust these lying sensors !
@richardwyn4642
@richardwyn4642 5 жыл бұрын
this is probably what wrong with my car. it wont even rev past 2000 rpms it drives fine just cut off if u dont let it warm up. im gonna change the 02 first while also checking for leaks. its an 05 ls lincoln i bet this does the trick
@bakutty91
@bakutty91 6 жыл бұрын
thanks humble mechanic. you are a great inspiration to me and many.
@isuruprasad4222
@isuruprasad4222 2 жыл бұрын
Engine runs lean after replacing the oxygen sensor. In the first 15 to 20minutes vehicle accelerates fine but after heated up it hesitates and vehicle doesn't rev up. The sensor is genuine and bought from the agent. What may cause this problem?
@sassy7482
@sassy7482 7 жыл бұрын
Very informative! Somehow, I knew exactly what you were talking about. I LOVE cars 💙💋💙💋
@arjrpzwork9416
@arjrpzwork9416 5 жыл бұрын
2 cylinders read bad st autozone.. Changed out coils... All coils going out over time.. 2001 f250. Changed last ones almost, after changed, went to autozone, had system lean and both cylinder reads.. Was not 250 miled yet to reset. Was reading from O2 sensor.. Will a coil issue cause a system lean reading from the 02? My heat is also jacked up.. Am wondering if low coolant levels could cause that. After coils failed, would see smoke coming out of engine.. Looked like a leak somewhete possible but dont know
@kramonut
@kramonut 8 жыл бұрын
Thanks for the vid Charles! Very informative! I have that intake on my GTI & love it!
@HumbleMechanic
@HumbleMechanic 8 жыл бұрын
Glad to help. Also thanks for the feedback on the intake. It's pretty legit.
@jonm2416
@jonm2416 Жыл бұрын
4:25 then why are there many videos showing a P2096 fixed after properly clipping a loose air box? Very confused. Please help.
@michaeltheut3481
@michaeltheut3481 4 жыл бұрын
My 07 gti has been in so many hands but no one seems to know why . I get a 171 system too lean only off idle and throws me into a limp mode with no power. I have replaced 02 sensor Purge valve Vacuum lines Brake booster Fuel pump Fuel filter MAF sensor Fuel pressure regulator Thrust sensor Hpfp Cam follower New air intake filter Diverter valve Rear pcv valve And I just put in a new downpipe with metal gasket all nice and tight It only happens when I'm in a constant steady speed or on highway cruising And also the engines tone after 4k rpms changes but only after 5th gear to 6th gear. I have spent so much and been thru so many mechanics They have pulled logs and all and they all say the car is acting normal when they drive it or they don't know what it is . I'm breaking my head here
@nickbaker111
@nickbaker111 3 жыл бұрын
Your videos are awesome and a great help. I could really use some help here. I have a 2009 Audi A3 2.0 L turbo. My daughter was driving and it just shut off. Before doing so she says it sounded like a diesel but its a gas engine. I towed the car home and began to work. I have since changed injectors, cleaned all the carbon out of the intake manifold, changed the plugs and coils, pcv valve, oil and filter, cleaned the mass air flow sensor, cleaned the throttle body, and various other bits of cleaning along the way. While doing all this over the course of a month I had the battery disconnected. I put everything back together and attempted to start and it cranks really fast but wont run. I am getting the following codes now: P0016 P0171 P0300 P0301 P0302 P0303 P0304 P0341 P0506 P12A2 Im not sure where to go with this now, could it be a broken timing chain?? Any ideas or suggestions would be greatly appreciated. Thanks.
@azcardz1869
@azcardz1869 4 жыл бұрын
Very clear and concise explanation! Helped me finally understand what that damn code means! Lol Excellent video. Thumbs up!
@giovannimora9134
@giovannimora9134 5 жыл бұрын
Peeping that chris fix sticker ;)
@joegarcia8447
@joegarcia8447 4 жыл бұрын
Giovanni Mora hi I have the same code did you figure out what it was thx
@davidbeaudin1106
@davidbeaudin1106 3 жыл бұрын
Loose gas cap caused system lean codes on my camaro Tightened it and everything was all right
@tomaslopez4322
@tomaslopez4322 3 жыл бұрын
Man so much good information, great video. Quick question, they did a fuel decarbonation and fuel duct cleaning and my car is back firing at idle and acceleration, is that normal for the first few days?
@robert-bg9pf
@robert-bg9pf 6 жыл бұрын
When you said that O2 sensor TYPICALLY but not ALWAYS peg out at max LEAN signal, I'm fairly certain it's based on your own personal experiences exclusively, and not influenced by what you have heard from others... My question is, how much of that supporting experience comes from ONLY V.W. / Audi ??? My gut tells me better than 75% stems solely from VW. Only reason I even bring this up at all is because based on my experience at independent shops where I have worked on just about ANY make and model of car in existence, it's a fairly even 50/50 split for O2 sensors to peg out either lean or rich when it kicks the bucket. I have yet to really find any rhyme or reason as to the causes of either death result... I feel a SLIGHT bias of Rich codes in American vehicle like Ford and GM. It may not even be real and if it is real, it's very very slight...
@elchinguengenchon
@elchinguengenchon Жыл бұрын
Will a fuel pump not being tight for a 2005 highlander give code P0171? I replaced fuel pump and not sure if that's what it is..
@bassment03
@bassment03 3 жыл бұрын
Just went to the dealership with 2014 vw tiguan system to lean off idle I replaced the pcv valve and the light came back on after clearing the code. Dealership says there is an oil leak from the timing chain cover and the pcv that i just put on is bad. I also have a water pump leak anywhothat's 2k out of my pocket and Christmas is completely screwed. I'll never own a turbo car again I just don't have the time tools or money to keep up.
@hyper-amps1684
@hyper-amps1684 3 жыл бұрын
I have a 2010 cc 2.0t, on new and old maf sensor the same p0101 on idle short trim 25% longtrim 0 for about 2min to 5 min until warms up, then short gets to 4-8 and long 40 - 49 on idle for 3min and on idle stabilized to short trim 0 - 48 long trim. It could be the wires? Intake No leaks the turbo whistle when driving and missfires p0300 to 0304 and the p0101 codes don't think is the cat plugged but Not sure. Thank you in advance.
@wyattoneable
@wyattoneable 8 жыл бұрын
I appreciate the explanation and insight.
@McDzy
@McDzy 7 жыл бұрын
Great name btw!! Quick question kind sir. If i'm planning on replacing my oem header and oem catback exhaust, would that affect how my car will run, lean or rich? without it being (tuned)
@fangounchained1235
@fangounchained1235 7 жыл бұрын
About a year ago I had some 02 codes on my v6. Ended up replacing all 4 o2 sensors. 6 coils. 1 cat converter and inlet manifold gasket. All good for 6 months now I'm getting bank 1 and 2 lean at idle codes..... All the long and short trim figures look good. What could it be ?????
@ryanchristensen1799
@ryanchristensen1799 3 жыл бұрын
Would old gas cause this condition? I found my pcv tube that went into the cold air intake loose and barely in creating a vacuum leak. When this happened my idle was rough and stabilitrak light came on. I didnt think I would make it home. My spark plugs were fouled. I cleaned them all and fixed the pcv tube leak with zip ties. I drove the vehicle several days later and it idled fine but my check engine light is now on and it gave me codes p2096 and p2098 lean fuel trims bank 1 and 2. With these codes set is that from the previous issue (vacuum leak) or is this now another issue (possible bad gas)?
@prestoc3034
@prestoc3034 6 жыл бұрын
How bout a short in a sensor wire. Could it cause problems with other sensors in the same part of the system?
@bernardliburd
@bernardliburd 3 ай бұрын
Can a missing gas cap cause it as well ?? Reason why is because lost my gas cap then that code came up
@larrygibbons6489
@larrygibbons6489 2 жыл бұрын
My son has an aftermarket exhaust with no catalytic converter and he is getting the po171 code. Could removing the cat cause that code ?
@wajeehulhassan2182
@wajeehulhassan2182 3 жыл бұрын
I have 1500cc petrol engine in toyota ...... I tried two maf sensor one giving 1.3 g/s at 650 rpm.... Another giving 1.7 g/s at 650 rpm.... Which one should i use for better fuel economy.....plz reply
@josephleeks8681
@josephleeks8681 6 жыл бұрын
Hi Humble, my 2006 Jettta 2.5 has the tendacy to reve up when stopped or idle, the RPM would rise without my pressing gas. My engine light is on, but still drives. Also my fuel gauge shows empty yet i have gas, drives and fuel light is not on. Please help. I love this car, so i am gonna invest.
@eav9183
@eav9183 8 жыл бұрын
Great video! I own an audi a3 2006 2.0t and install an hks BOV, at first it was great but after some months my check engine went on with rich conditions. After scanning and wondering why? I discovered that the BOV was In some kind confusing the ECU, so i took it off and problem fixed! Great video indeed! Greetings from mexico city!
@insylem
@insylem 8 жыл бұрын
I had a system lean fault. I took my car in and they reprogramed the PCM to add more fuel.
@trainer2018
@trainer2018 8 жыл бұрын
Charles how about collect some bad parts, air tubes, maf sensors, o2s, install them and then show different diagnostic scenarios while you work on the project cars, that way you can work on them at the same time and then show videos too. Then also show the scan data when these problems occur.
@HumbleMechanic
@HumbleMechanic 8 жыл бұрын
+busjockey1 man that's a great idea. That is a long term type project type thing, so it may be challenging.
@Sicktrickintuner
@Sicktrickintuner 8 жыл бұрын
+HumbleMechanic maybe you can put a list out and people can send you bad parts if needed to test and show that you don't come across often enough.
@matthewholcombe5996
@matthewholcombe5996 3 жыл бұрын
I replaced my valve cover gasket and didn't fully connect my fuel line wiring harness .... so stupid but I corrected the fuel lean error. 😂
@tonyjohnson9964
@tonyjohnson9964 4 жыл бұрын
How bad is it to keep driving my 05 chevy cobalt for now until i have someone look at it
@jabarrmohammed1204
@jabarrmohammed1204 Жыл бұрын
Hi charol I own a 2010 Tiguan I put tow set of brand new spark plug turn black sooded on the tip top of spark plug and misfires help me please
@GalaxyXTV
@GalaxyXTV 6 жыл бұрын
I have 08 Passat 2.0T 122k miles. CEL is on. P0302 P0171. CEL is on. I changed all sparks/coil. And now the CEL is still on for P0171 system 1 too lean bank 1. But after changing spark/coil. I get a random misfire with the random shaking sound from exhaust then white smoke coming out. Can it be the 02 sensor (downstream) that’s causing my misfire and system to lean?
@reddmann1168
@reddmann1168 2 жыл бұрын
Hi I replaced my turbocharged, and got p0171 and p0101. And cannot build boost. Waste gate is opening to soon
@adrianparada5950
@adrianparada5950 7 жыл бұрын
great informative video...keep em coming
@gxoticbirds9282
@gxoticbirds9282 3 жыл бұрын
I have a 99 Toyota Corolla ce and Im getting that same code P0171 what should be the first thing to check
@minnesnowtan9970
@minnesnowtan9970 8 жыл бұрын
I'm new to VW, and never heard of this condition. I really learned a lot and like your explanations. How do I send individual questions to you?
@sgtvoncarstein592
@sgtvoncarstein592 5 жыл бұрын
I have saturn ion i put a short ram intake in but there is a secondary air injection hose out and i get a check egine light idk to replace it back to stock or try n remove the hose
@salvadorvela3727
@salvadorvela3727 5 жыл бұрын
Thanks. Nice explanation
@87studga
@87studga Жыл бұрын
I have questions so I have a Toyota 4 runner and I got a crack in the radiator housing holes so it broke off where you connect the hose up to the radiator so I have to get a hold of the radiator. But could that be a problem as well is P0171 code popped up? I had checked all the holes and I noticed the the crack was at
@ryanclements8320
@ryanclements8320 Жыл бұрын
Hey, I have a old peugeot 106, And my car will idle rough when sat in traffic, I've put a new icv valve and oxygen sensor on cleaned the carburetor with no luck, i have noticed after changing the spark plugs noticed they are coated white. Does this mean it's lean on fuel? It drives fine other than this fault
@Abdullah-hc1cz
@Abdullah-hc1cz 2 жыл бұрын
does weak fuel pump can make the engine issue to be a high gas consumption??
@martinalbert5653
@martinalbert5653 4 жыл бұрын
I replaced the O2 sensor because a mechanic told me to replace it. Did not fix the problem. Is replacing the 02 sensor first the best choice. The scanner said running lean Bank 1.
@SleeplessinOC
@SleeplessinOC 4 жыл бұрын
Martin Albert did you ever fix the problem ?
@JL-sy1tl
@JL-sy1tl 3 жыл бұрын
Seems like my 2006 silverado is running lean but I have no codes. Can it be the catalytic converter? My rpms are low. Transmission is fine.
@ariscott7029
@ariscott7029 4 жыл бұрын
Hey Charles any chance of a video on system rich
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