My neighbor used the Bic lighter test on his EVAP hoses....once. I miss him.

Finally, an actual teacher to teach all of us old school mechanice, these modern computerized cars. Thank you Sir, Salute.

Well explained.We need more professional advisers like this man on you tube.

Good to see you back again. The way I was taught, basically open loop means that the computer isn't using the oxygen sensor/s to determine the fuel control strategy. It uses the TPS, MAP, MAF, and all other engine input sensors, but ignores the oxygen sensor/s reading. Closed loop means it uses all of the above plus the oxygen sensor/s.

First thing to do, replace the gasket on your gas Cap. Esp if the car is old. this will cost you around $20 or less. I got this evap code, reset it, a week later it came back, I checked my gas cap and it didn't really feel snug like a new one, so I checked online and I found a recommendation to replace gasket. worked for me.

Absolutely one of the best instructors on KZfaq. I appreciate the time you take to instruct and teach. Thank you

Thank you for making the video. You are a natural teacher. I really appreciate the background information that really helped me understand how the evap system works. I assume that, if the purge valve had been good then the next step would be to pull and check the valve by the gas tank. I think I will be able to fix my car now thanks to your video.

Not sure why people are saying this is too long. It’s a great explanation. Nice to have an understanding. I don’t need the expensive machine because most auto parts stores can get you the code. But I do like to understand the big picture in the system that I’m throwing parts at.

Initially I was disappointed not seeing the direct fix, but once you got to the details, I began to appreciate the video. Really informative and educative.

THANK YOU THANK YOU THANK YOU!!! This was totally the problem.. Changed the purge valve $42.00 @Advance Auto.. 15min to change.. Mechanic charged $40.00 for his time.. Awesomeness.. Pass Georgia emissions no problem!!

One of the best explanations i have EVER seen.... you explained the entire cycle.... I keep getting "Depollution system faulty" in Peugeot (its a plague in these cars!), i even have thier Computer the agency once no clue yet.... it causes the car to go rough and engine to rattle. I'm doing the smoke trick near engine and going to check the fuel pump (checked the fuel filter seemed new, and cleared it myself even)

I thought the info was very informative and it helped me to understand the evap system much better. Thank you for making these videos!

Good to see you again. The quality of your instruction is superb!

Thanks, You are by far the very best teacher on KZfaq . I learned a lot from your videos.

great instructor I like the way you explain the system before jumping into the repair well done.

I'm ready for part 2....glad to see you posting again

I like your critical thinking. You used the knowledge of the computer to help you determine a solution. GREAT!

Awesome video, both parts. I don't consider myself a "car guy", just a "cheap guy". I hate to pay someone for repairs I can do myself. The evap system was always a mystery to me. Thanks for the thorough explanation, so I'm not just shotgun throwing parts at it. My hat is off to you kind sir.

Very well done video. Good explanation of the evap system. If you don't have a smoke machine this is fast and easy way to troubleshoot the system.

You'd make a great teacher. That was an informative, succinct description on EVAP. I do pray that my trouble are only a gas cap with the p0456 code. Now onto part 2

Great video. Really shows how generic troubleshooting techniques always remain valuable. A note to young mechanics, use your head and pay attention. Your time will be spent less on troubleshooting and more on helping your clients and that makes for return customers.

Excellent Video ... I appreciate him giving the thinking and diagnosis process!!

GREAT TEACHING, I AM REALLY LEARNING ALOT, FROM PART 1 and 2, I also have a small leak, engine LIGHT IS ON, going to test my test my PURGE VALVE.

Thanks for doing this video. You always do a great job. I know to make a video takes time. I appreciate you sharing your knowledge and experience.

Excellent teacher! That video time flew.

This man is a natural teacher.

Awesome video - really helpful in understanding the foundations of the problem. Thanks for making this!

IT is always good to see you back with videos full off good info always.thankyou

You truly understand your craft! If you where anywhere in upstate NY you’d be my mechanic and my whole families until we died

Great post. I just hate the fact that these critical valves (purge and vent) are such a pain in the butt to get to. My 2006 Avalanche is a real pain...

sure appreciate your videos wish i had more years of life left to understand all you do, even then i wouldn't, memory is a downfall of mine. thanks for your videos. you know allot electrical, mechanic etc. thanks again for illustrations.

Great comprehensive instruction on EVAP systems and their repair. Much appreciated!

This is so amazing. If you can pay some attention and listen, you will end up saving a lot of money, but then again you need some common sense to do that. Absolutely awesome. Thank you sir.

nice explanation on how the evap system works!

Thanks for this video, great explanation of the system. Thanks for sharing your knowledge.

Very well organized and executed. Good job.

I am glad you are showing how to fix a leak made easy,

Thank you for your time and efforts stay blessed

Best explanation I like your way of teaching thanks a lot

Wow, not surprised, but people have short attention spans. I guess this sorts out the good mechanics from the mediocre ones. Really appreciated this video and thought it was well instructed and well produced. The point he makes (which those with lazy attention spans will never understand) is that a little critical thinking in advance and a good understanding of how the systems work saves time and parts costs in the end, because rather than just diving in and randomly swapping out parts (at your customer's cost), we try to pinpoint the most likely cause of the problem from the start using the information the car is giving you. The answer is there - but you need to learn how to analyze the data first. Too bad more mechanics don't take this approach. Will be watching more of his videos. Totally impressed.

Excellent tutorial. Thank you so very much~! I'm a 70 year old woman and my 40 year old daughter and I are determined to fix this problem. LOL. However, if I were near you, I'd bring it to you for a fixin~!!

He broke it down he's very knowledgeable and it makes sense I gave be a lead thanks thanks

Highly appreciate the video! Great explanation

Awesome video ! You are a great teacher .

I've not even watched the video yet but we have missed u! welcome back, sandy from Scotland

I can’t believe I’ve never seen this video. Oh well catching up now! Thanks Dwayne!

BEFORE you watch this long video, which is well done, know that it is not about "How find a small evap leak without a smoke machine" but rather is is about how to understand the evap system and use an expensive professional scanner, IT IS NOT ABOUT HOW TO ISOLATE A LEAK (hopefully that is in part 2, yes there is a part 2 even though this vid is not called part 1.

Thank you for posting this video!

Thank you. Very clear & informative!

Great explanation video and visual examples! Thank you

Thank you!! All you ve said is important and interesting.

GOOD JOB i like you explanation very clear thank you

Perfect video I just notice I think someone else mention your channel before I see why

I haven't seen a video from you from so long!! your videos are always great and informative !

THANK YOU FOR THE VIDEO YOU ARE A GREAT TEACHER

This was extremely informative.

Pop, your a great teacher

AWESOME information here!!! Thanks for sharing your knowledge and experience!!!

This is all for OBD-II vehicles that have scan tools, PID's, and enhanced monitors. OBD-I (vehicles made before 1996) have it much harder. Still a great video. The diagram and description of the evap system is spot on. Not all vehicles have electronic canister vent valves or pressure sensors. Have to take all of this into account when diagnosing a vehicle and adapt these procedures for the vehicle design that you are working on.

Great explanation of the system and troubleshooting

Thanks for explaining how the EVAP system works. I like to have knowledge before taking my car to a shop. Ignorance is costly. ☺

Great video, thanks for the expert advice

A very good and informative video, so funny some people commented the video that is not helpful or saying that too much of a talk. If you guys are only thinking of fixing the problem without understanding what is happening to your engine there's two things thst might gonna happen, either your car engine problem migjt get worst or you fix it right. I like the way he explained everything as i clearly understand how things works👍. By then if you send your car at the shop, those greedy mechanics will not be able to fool you the way they steal money from our pocket. Regarding with the tester he used, he's not promoting and or selling what he's using i guess, it's just that, that's what they are using in their shop? We shiuld be glad and appreciate this kind of person sharing us some information what to look for if there's some problem in our car engine.

Very informative now I kinda understand how it works it will help me no what to look at thanks

it would be nice if they taught that in school, 'critical thinking' thanks and many Blessings Duane : ) excellent presentation

Great video. Thanks!

I like the way he explained he has a lot experience

Nice review, Duane!

Very informative. Thank you

After watching parts 1 and 2, a smoke test would not find this type of small internal valve leak, so we get a lesson on second level diagnostics for evap. To those critical of his fancy computer, getting good data need not be expensive..Various OBDII scanners are avail from ebay or amazon for like $22 (bluetooth to smart phone) or USB to your laptop. You can download and use several free apps or buy cheap add-ons to decode much the same data as the $4500 computer produces. The main limitation is your investment in time and understanding how to maximize the apps and what the significance of the data is.

INVALUABLE CONTENT! THANK YOU👍

this is very professional (MTM),I have watched your videos for years , Im glad to have found you videos and teaching, I have made a donation. I will subscribe t o your channel

I just subscribed to your channel. You are a natural teacher and great at it. After watching this video and pt. 2, I learned more about my vehicle and how it works. I think it now helped me to know what to look for as the engine codes come alone or my CEL stays on like it's staying on now. My mechanic is currently in the process of replacing my PCM on my Honda Accord v6 because we have gone through every repair or part replacement you can possibly imagine, but the CEL never stayed off. We think it needs a new PCM/ECM which is what the first auto repair business told me too. I want to get a diagnostic tool like you have. How much does that one cost?

Great video help me a lot,thanks

GREAT Content Videos Thank you so much

Nice explanation, Duane. I've never found Freeze Frame data to be valuable for diagnosing EVAP systems, since the monitors generally run at cruising speed, but the test result/MIL command can be issued at any time...any thoughts?

Very helpful thanks I'll will try to doet myself.

great vid as always...

Thanks for this straightforward clean video. I keep getting 2 codes at the same time P1092 & P1093, Pre cat trim too lean and too rich on Bank2. How is this possible. Or is it because something else is going on. Be grateful for your response.

To add to my previous post about checking the easiest thing first and my issue being the purge valve on a 2015 Charger, it took more than a squirt of WD-40 to loosen things up. The valve required some throttle body cleaner as well as a couple shots of WD-40 but I think it's finally loosened up. One thing of note is that it's NOT a completely ON-OFF type solenoid in my case. Bluedriver OSB-II shows that it is analog in nature meaning it's variable. New valve is about $25 without tubing to manifold or about $40 with tubing to manifold. This matters because tubing to manifold is difficult (but not impossible) to remove from valve.

mmmm,,, I guess I still keeping my 1975 Chevy,,,, those new vehicles have so many sensor$,,,

I dont have that costly machine either, nice info if you have that code reader , yes a waste of time for most of us. Thanks just the same

A small evap leak could be sign of bigger problem. I had p0442 code too and thought it was a small problem. i did exact thing what u said on video and couldn't find anything. So i tapped out and took truck to shop. they smoke test it and found out i have a small leak coming from top of gas tank where sending unit and sensor is located. if u have older car thats rusty underneath i advise you to have the shop trouble shoot for you.

Best explanation Sir. Thanks💐❤️💐

Great explanation for the EVAP syystem. Always goes bad on Fords

Very well explained thank you

this is the best mechanic i have seen ..............he know his shit...

Thank you. Great video

thanks this video is very helpful.

Very informative!

very educative. Thank you Regards

Buen video amigo exselente maestro

Great info. Thanks.

Thanks a lot it's very helpful

Very nice explanation

Good stuff... Thank you

thanks for this detailed info

Great video!

Everyone is a teacher, but not everyone is a good one, and you Duane, you are a stand out! I have a few questions. In order for the monitor to check for the leaks, both valves have to be closed. How did the canister vent valve close? since it's open when the engine is off. On the large & medium leaks, system passed, , how do you interpret the values shown? what I mean, how would you know whether those values are optimal, or on the borderline of a leak? Again, thank you for video and the wealth of information

I have to say....I need you for my teacher