GM "P0455 Large EVAP Leak" - What To Check When It's Not The Gas Cap

[@jamieprice126]

I have been a mechanic for 40 plus years and I would bring my vehicles to you for repairs if I lived in your area 2 thumbs up

[@masapell]

This channel is like taking an online college class for free! What a great explanation!!!!

[@chrisl4999]

My vehicles money light came on and the local guy wanted $1500 to replace the evap solenoid, canister, and 2 o2 sensors. Watching your vids, i did it myself in a couple hours and $200 in parts. Thanks!

[@govindagovindaji4662]

"Money Light" ~ lol, you got that right. Very clever & funny~!

[@bryonhalsey6033]

It's nice to see someone knows how to use the test equipment and understands how the system operates. That way he is able to diagnose the problem, fix it, and isn't just a parts changer. He has my vote of confidence, that I'd feel safe letting him, to work, on my vehicles.

[@klwthe3rd]

Another great example of how an Actron alone will lead you astray. Understanding the data in the bidirectional scan tool is the key to leading you to the root cause. Great tip!

[@josephmoniz4109]

Great job explaining the issues with these EVAP codes. I wish I had the scanner to switch solenoids off/on command. That really helps the diagnostics move along quickly.

[@wendwllhickey6426]

Those valves always stick open or closed they have trash in the valve that makes them stick

[@knobrush]

My father has an '03 Chrylser Town & Country 3.8L and it has P0442 and P0455. "Upon visual inspection" I found a brittle gas cap gasket and two split hoses in the evap system (luckily within easy reach). New oem gas cap and a bit of fuel line...good as new and only cost $20.

[@epipolarus]

Impressive work! I don't own any GM cars, but I still learn something from EricO, every time. In my opinion, Eric O is the best mechanic on youtube. If I could find a mechanic like him, I'll quit DIY.

[@wranglersdirect2803]

Wow I stumbled across your posts for the first time. I wish every one else's video was as thorough and informative as what you provide. Well done I hope your getting paid well for your above average ability. Thanks for the effort and nice Job Ann with your side of the video.

[@SmittySmithsonite]

Great info. EVAP is one of my weakest spots in automotive diagnostics. Been learning how it works in bits and pieces from you and Paul D. over the past year or so. Glad you used the Autel so I know where to go on GMs now. THANKS!

[@xelaju8]

I like your scanner. I am sure is an expensive one. Most people would get bored watching this but I definitely understood what you did. I recently had to change my evap line from the canister to the purge solenoid and got rid of the mil. I had to learn how the emmission control system works here on youtube. The good thing is that I have a strong background in electronics and HVAC. which helped me fix these issues on my Chevy Cobalt 2009 and save me some money. You are right We can do it. Thanks for sharing your knowledge. Nov 2, 2020

[@waynemintz5361]

I love watching you , I own nothing new, But watching you, you have steered me in the right direction to find my problems with my 1994 Plymouth Grand Voyager 3.3 engine , my 2004 S Type Jaguar 3.0 engine and a 1999 chevy Truck 454 engine. I have my hands full trying to keep everything going. You are GREAT thank You.

[@CarlosAGarcia97]

"The money 💰 light is on " never heard that phrase before Never will Forget it !!!🤭😏

[@natetransitions8379]

I have a p0441 instead for "incorrect purge flow" but this video really helped me further understand how to command with scan tools and what to look for. Thank you.

[@TA_Freak]

Great info! Thanks! I went from a PO449 to a PO455 after I replacing the evap vent solenoid on a `08 Corvette. I verified that it was faulty by applying 12V to it. I'm going to replace the gap and if that doesn't resolve the LARGE leak, this will help!

[@Jay_Dahl]

"The money light is on". That made me laugh. Great humor.

[@kellyhouck3969]

True that!!!! It is the" Money light" it's on it's gonna cost ya lmao

[@Mr_Ulm]

I never heard any one, not even a Tech, say "money light" thats great! LMAO!! I will say that to my Tech next time i ask him to pull the codes. lol

[@lildezyvert]

ain’t that the truth lol

[@scottieboy69]

Depends on which side your on,mechanic, or owner. Wether you want to cry or laugh .....,.) =

[@narrowhwy114]

Saw a bumpersticker on the back of a Ford explorer that had the money light on it with the message, "This little of mine, I'm gonna let it shine!"

[@JD-526]

Excellent I'm going to do the same test with my truck because my check engine light kept going on and off at different fuel levels, I hooked my Verus to the truck just now, and it said I had a large evap leak again. This is the second time I had that code come up, So we'll see. ( Update ), did the same test on my Silverado the purge valve was bad, was able to bring it back to life by tapping on it. Thank Eric you are the man.

[@GoTechTraining]

Great vid showing a purge issue. Leak codes can be deceiving! I love the test where you close the vent and see if you build pressure or vacuum. What a quick easy way to verify if a leak is present. Have you ever run into issues where the scan tool times out before you are certain of a leak being present or not? Thanks for the links! ~Mike

[@satamanschmidt3428]

Very good Eric. Simple, direct and to the point with solid explanations as to what's going on. Denny liked it. AND it was a lot more interesting that watching you solder wires for two hours.

[@HToWnRePPiiN]

So I replaced my purge solenoid, drove it like 120 miles, light still remained on.. I then went to youtube, watched this video, went outside and checked my brand new purge solenoid and realized it wasn't sucking, tapped it a few times and it kicked on and it made me feel like a million bucks lol. Drove about 65-70 miles and check engine light went off! THANK YOU!!!!!

[@buzoff4642]

Oh man!, is that bad news. New one is bad???

[@fauxhawksexipapi]

Bro I swear to god, I was stressing out for an entire year and you gave me the answer that I needed I knew I would find the answer in one of these videos, thanks so much, you have a new subscriber

[@Maxim.Teleguz]

What was the answer and did you actually do a repair.

[@danalarose846]

You may have just found the problem ive been having for 7 years, thank you.

[@ivanmanzo9207]

My 08 avalanche had this issue, spent couple hrs looking for leaks with no luck. I'd u don't have the scanner to do it, just unhook the hose from the solenoid to the intake with engine running. Plug the intake port and try to suck air from the solenoid . if u cant, then ur solenoid is bad even if it clicks. Great video. Can't thank u enough!

[@samphillips8322]

Very helpful video. Just about everyone in our extended family has had an evap issue at annual emission test time. I have noticed the online manuals for some European imports show the Evap system as well as the startup air pump and solenoids have the notation "USA ONLY" and the build sheet likewise. IMHO this is one emission system that probably causes more trouble than it is worth. If you ever decide to move south, you will feel right at home.

[@shawnwithee6336]

Thank you for your simple but somewhat confusing explanation of a problem I seem to be having with my 2003 gmc envoy sle. I don't smell fuel or see any signs of leaking from hoses or tank but my truck seems to lose gas fast most of the time so that's why I said confusing. I'm old school mechanic now I'm just a parts changer with the valuable advice from you a true professional mechanic. The Mackey mouse code readers from local auto parts store don't give in depth troubleshooting like you have here. I grew up with Chilton manuals and no sensors and plastic parts with over thought bad designs. I will change my evap sensor when I get the extra cash and again thank you for this video your time and freely giving your knowledge to me the guy that can't afford someone else to do what I can and like to do myself.

[@MrThebrinksman]

You are the man! Very informative and extremely helpful. You have helped me through what I needed to know. Things that the book won’t even attempt to explain. Thank you very much!

[@buzoff4642]

"Very informative" Good! How does failure to purge, equate to "large leak"? Bad software?

[@andrewtheautotech]

@@buzoff4642 the computer sees the pressure not changing because the purge is closed so that registers to the computer that there is a large leak because if there was a large leak pressure would stay the same

[@buzoff4642]

@@andrewtheautotech So, bad simplistic software. Leak, invoke pressure and pressure does not rise, or rise above X. Bad purge valve, pressure rises but then does not drop upon OpenValve.

[@andrewtheautotech]

@@buzoff4642 yes exactly. That would be the only way it would make sense for it to throw the code in this scenario. Crappy computer logic to me.

[@buzoff4642]

@@andrewtheautotech Yes. And furious use of our cars is hostage to it: Check engine on, no inspection sticker, no legal use. Worse, local mechanic said OBD was for purpose of emissions and safety, but now includes items that are neither emissions nor safety, but merely less than optimal performance. Really chaps my hiney.

[@noelcastle3986]

Another great diagnosis with well explained procedures and system.ooeration . I could see how it could easily be misdiagnosed. Interesting how you could see the PWM making the test light flicker must run a very low PWM frequency .

[@GlycerinZ]

If you inspect your purge solenoid and you see charcoal bits, make sure you replace your charcoal canister in addition to the solenoid! Don't just replace the solenoid or the bits of charcoal will cause it to get stuck open. Happened to me in my Trans Am

[@gordonfreeman5434]

Eric O is the Jedi master of the auto repair world.

[@elcheapo5302]

Any day that starts with a new SMA video is a good day. Thanks, Eric.

[@lukecartwright1803]

Im so grateful that u started making youtube videos!!! I truely am. U are just a natrual at it.

[@johnclunan4488]

Wish I lived closer to bring our cars to him, always a Masters Class

[@jeffdowning4877]

Awesome. I had the exact problem and I assumed the P0455 code was accurate in that there was a major leak, yet I could not find it, and I ruled out the purge valve since it was closed tight with engine off as it should be. I had not thought about it being stuck closed because then it would not be a leak but the opposite- a pressure buildup. I would have had no idea if you had not mentioned it that the code could be a misinterpretation. It was the purge valve. Thanks sir!

[@ocrun6765]

Smart evap diagnostics!! Thanks for making this video.

[@wysetech2000]

Evap testing and repair simplified. Nice job, Eric.

[@STREETSTANG07]

Thanks again Eric always very helpful especially when using the Autel ms906. I had same problem on a 2009 Kia Optima the guy was throwing parts at it looking for someting big and one give away was he said hard starting after fill up. Thanks again. P.S. I'am doing a head gasket on 2006 Subaru Forester your video on that was the best. The newer one have a variable rocker arm timing but still pretty basic.

[@thinman8621]

Always appreciate help with evap systems. And hope it's not BWD when you replace the failed part.

[@stevethatcher599]

Best comprehesive video on common evap issues I have reviewed.

[@KingOfKYA]

On older cars also good to check the filler neck hoses, my sister explorer hose was bad enofe i crushed it into dust with my hands. then the evap issue went away after i got a new one.

[@benjaminstockton3431]

No smoke, No brake clean Good job Eric o. Thanks for video's

[@joerhodes6626]

Very good video. Absolutely very informative. helped me solve a problem on a GMC Terrain that was just driving me friggin crazy!!! Thank you.

[@aim321fire]

"All you have to do is wack it with screwdriver lady!" Too funny..Haha

[@Sandbag1300]

Nothing like waking up to a game of whack a mole with the purge solenoid. Great diagnostic. Thumbs up video.

[@stacydornan9765]

Once again another spot on diagnostic, your the man Mr.o.Good job bro

[@terrancedesormeauxjr2559]

You my friend just saved and helped me diagnose this problem on my 05 Tahoe. Subscribed

[@2eagle86]

Man it was boring all weekend without a video! about damn time a video was posted!!

[@EduardMontilla-n1e]

Brother keep doing videos like that!!! Always explaining cause/options good job

[@wmshannahan]

You did a great job in explaining you process. And now I'm pretty sure on what I have to do next. 13:25

[@billrimmer5596]

What I meant to say first was. Super good video. Very comprehensive way to check out evap codes. Will b consulting on a regular basis. ThAnk u!!!

[@Paul1958R]

Great video as always! Obviously cannot diagnose this without a bi directional scan tool that the average guy wont have. What is the least expensive bi directional scan tool on the market? God Bless. Paul

[@GNX157]

Back in the mid to late 80's I replaced a shit ton of purge valves on the 307 Oldsmobile engine. The diaphragm inside would leak and allow tank vapors to pulled thru to the vacuum control source. Every car that came in with that engine, we'd check it first thing, regardless of what the complaint was, that's how bad it was.

[@Rose-ht4tq]

How do I find an honest mechanic like you???

[@victorvillasana3409]

Rose with a camera videoing the repair, 😂😀

[@mrsemifixit]

I got a challenge for you and other fellow mechanics: 98 civic. Get code p1456 (small leak gas tank side) changed gas cap with OEM, 2-way valve and bypass valve. Code still returns. But here's the only clue I have: on really hot summer days the monitor system passes the leak tests every time. When it gets colder out the code returns all the time. Ran a smoke machine through it and no visible smoke coming out anywhere

[@satamanschmidt3428]

Easy Peezy, Move to Phoenix, it's always hot so you'll never have this problem.

[@heyitschinoable]

mrsemifixit Idk but to me seems like you have a really really tiny leak. The one clue that leads me to it; on really hot days it passes right? Well with hot temperatures materials expand sealing the leak. On cold days it contracts and the monitor picks up on the leak. I wonder if theres any metal evap lines on that thing. Id say smoke it on a very cold morning. 🤙

[@colassolorzano6353]

mrsemifixit do a smoke test but remove the sear and the fuel pump cover plate and see if any smoke come out..

[@codywichman213]

I've ran into this before. There is a check valve type thing in the canister. Also you can verify by sealing one line at a time from the bypass valve, one line is for the tank one is the canister, if you pinch off the tank side and run the evap service bay test. It will no longer have a leak. Also the canister is sold with the vent valve. On older Hondas the vent can be the other culprit

[@codywichman213]

Also when your smoking it. You can pinch off the lines at the bypass valve, and make sure you go over everything with soapy water, make sure your using a jumper wire to ground the canister vent, if you plug it off your not gonna be able to test it obviously. You may need to close and open it a few times also.

[@bookofrevelation4924]

Can we test for evap system failure without a tool to read computer by letting gas tank level drop below 1/4 tank to see if light goes off, then if light goes off from not testing evap system due to low fuel level, then fill above 3/4 to see if light stays off, and if off until fuel level drops below 3/4 before light turns on again, then the light is likely on from evap system? And purge valve most likely the problem as hardest working and moving part in the evap system? Gas cap for 15 dollars is tempting to try for a quick cheap fix, but not likely to get damaged before the moving purge valve wears out. Thanks for video, I learned allot.

[@RodgerMudd]

Yep that's why I am changing cap first.

[@bookofrevelation4924]

@@RodgerMudd before checking operation of the purge valve, which operates more than the other parts, and seems most likeky to fail before other parts in that system? I would pay the price of a gas cap to have the purge valve tested first. I had my mom fill up her Jeep Liberty to see if light goes off and it has not yet, she had it reset once and retightened gas cap, but light came back on. Might have her reset light while tank is full to see if it comes back on, and write down the code if she has someone read it again. She had someone read the code and tell her the computer said it was the gas cap, but she did not know there is a code and testing process rather than the computer simply saying directly it is the gas cap failing.

[@RodgerMudd]

I changed cap today. The code is not on right now since I reset yesterday. I will also fill the tank. The code was popping up right after start up according to the freeze frame data on my scanner. Cost so far 18.99 locking gas cap. Thank you for the reply. @@bookofrevelation4924

[@ryanallen4346]

Dude, you are a beast. The guys at Belle Tire would think you're a god.

[@nicholaswilson5671]

Another day in the life video needed. More snapon of matco tool truck visits, or a toolbox tour video

[@brianstaples4057]

Great video as always Eric. My 2007 Chevy Impala at idle holds -100 pa and -350 pa running down the highway. Not sure if the solenoid is stuck closed or open. I have a scanner and vacuum gauge, this video should point me in the right direction. Thanks my friend.🚗🚦Let's see if I can do it to, yes?😉

[@yoiamthedude]

Excellent info video, Been scratching my head with problem for weeks. Bought the new evap solenoid and sure enough that was it. 2003 Jeep Liberty Many Thanks!!!

[@dentondunn4346]

I'm having a large and small leak on my 03 Liberty. Did it cause yours to run lean on bank 1 and make it through a 02sensor code as well? I'm having those issues

[@wyattoneable]

A noteworthy case study and once your on the right track, an easy fix. Thank you for that one. This may seem like a strange question to ask in public but is your lift capable of supporting an 8000 pound Dually? I have an idea.

[@AntonioClaudioMichael]

Simple Diagnostic tests you definitely can be lead down the wrong path with these evap codes it is definitely stuck Closed good Work as Always Eric O @SouthMainAutoRepairLLC

[@kas0016]

I think everyone hates evap issues. Even with knowledge and understanding.

[@klystron1]

i always hit like before watching at 0:01.

[@hanskinslo326]

Me too!

[@ShainAndrews]

Nobody likes an over achiever. 0:02 ;-)

[@InsideOfMyOwnMind]

Good habit to get into when you already know you're gonna hit three 7's. I'll have to remember that.

[@feeneysmechanical6215]

klystron Same here I hitting the like button. Imagine if Eric taught classes. It would be mind blowing

[@jeffheld3971]

Let me tell you - after some initial trial & error I found a couple of your EVAP vid’s which helped me isolate my P0455 money light! All I have is a basic Actron scanner / code reader. I had voltage at the vapor vent solenoid and thought that should activate every time the key was turned on. Since it did not activate I thought it was bad and replaced it. Cleared the code but the $ light came back. Checked the fuel tank pressure sensor but could not verify its operation. Decided to replace it. Since the P0455 was permanent by that time I had to perform a couple of drive cycles. No more P0455! I’m also baffled by the seemingly specific GM drive cycle “requirements”. Who the heck in NYS has a or no enough or straight enough Road - with no traffic - to run that drive cycle uninterrupted? Anyway, thanks!

[@marcinmorris]

You're like 5 stars hotel among surrounding motels ;) Best as always!

[@rrmech11]

Eric I really enjoyed the refresher in the GM evap system

[@walter.bellini]

Thank you for the great video Enjoy the process that you explain as you go through trying to find the issue.

[@kylewoodward7078]

The money light is on...lol..love it. That's the damn truth!!

[@Twiggztravesty]

So very helpful and informative. Very great explanation for how and why things are acting the way they are. Thank you.

[@jameshrenn]

That scanner is a definite plus and time saver 😎 $$$

[@schigara]

My last flip was a 2006 Equinox. It had no gas cap when I got it so I got a cheapo on ebay. There was a stored code for large evap leak so I figured of course the missing gas cap was the issue. After installing the new ebay cap, the large leak code came back so out of habit, I pulled the purge valve and it was stuck so I sprayed it with wd40 and tapped on it until it clicked and held pressure reliably and then reinstalled it. It still had the large leak so I built a diy smoke machine and the new ebay cap was leaking like crazy so I bought a gas cap from Orielley and it also leaked like crazy and you could feel they didn't get tight at all after a few clicks of clockwise rotation they would very easily come loose with very little counter clock rotation. I went and got an oem cap at the dealer for a few dollars more and it tightened up nicely and there was no longer a leak with the smoke machine. The oem cap got very snug and took a good amount of force to remove it and it had no leaks with the smoke machine. The plastic lip on the aftermarket caps just below the rubber seal was only 2-3thousanths of an inch larger than the oem cap but that was enough the keep the aftermarket caps from pulling down far enough to make a tight seal with the rubber grommet/oring. This is why they took such little force to remove. These aftermarket new gas caps can also be an issue with large evap leaks on this Equinox and Torrent that you would never find without a smoke machine.

[@clarkgarber5495]

Duc Rider, I haven't used aftermarket gas caps for decades. OE only if you want it fixed. Can't believe they even sell them cause they don't work.

[@pontiacsrule8761]

Another great video my friend. That always drive my nuts with those evap codes

[@grominwithrob1339]

I miss the days when mechanics diagnosed problems instead of shot gunning parts at symptoms. Even doctors don't diagnose anymore. They just give meds to hide symptoms. 😓

[@cognac8297]

Their Pill pushers and insurance thefties . And each new doctor just learns off your body. It's a joke it's a money joke . They can't even fix themselves

[@DJR5280]

You're on a GM upload frenzy lol. Love the vids.

[@razor4059]

Thank you for the detailed troubleshooting! Loved it!

[@SuperFatrock]

I've had the Purge and The Cannister changed lord knows how many gas caps and still i get P0455 code.So i guess I'll check the purge to see if its opening or closing.

[@waterguy5924]

Great Explanation Eric...never disappointed !!

[@bobcajunwon9552]

These evap tests done by the PCM do not impact engine performance, they mostly serve to cause headaches and cost money at the shop. This evap diag can be tuned out less expensively and permanently.

[@jimzivny1554]

Good video, it would be interesting to see the valve cut open to see what is bad, I've never seen that style.

[@mechanicchaz7639]

U can also use a smoke machine as well... that's what I always used ... but this the way u do it is very cool and informative!... I'm working on a 03 kia sedona 3.5 every time she fills it up .. the van wants to run poorly even stalls... and you'll have to keep it revved up until about 10 min sometimes more... I'm thinking a other valve is stuck open or charcoal canister I live in Maryland we get lot of rust as well... if you see this comment can u give me any tips or tricks iim a mobile mechanic cause I'm a single dad I do have code scanner but nothing that nice... any help would be much appreciated and love ur channel funny dude!

[@haywardsautomotive6156]

The ole tap test...if it doesn't work tap on it & if it doesn't work then hit it harder. :D Nice diagnosis & repair video as usual!

[@trackerrrr]

Thanks for the great video. I have a buddy with an '05 Equinox that is doing this randomly with a new gas cap so now I have a good idea what to look for.

[@motorcyclesandridingfree2899]

Wow first to hear of somebody rotating gas caps lol that is hilarious. Good job Eric

[@davidnie2062]

Thanks for going thru the steps to diagnose the problem. I have the same code reader and it helps me get thru the diagnosis. Curious if you could throw some advise out for a 2500hd with random misfires on cylinder3 and 4...dont know if you do things like this but I've pretty much have been done the rabbit hole with this thing and am running out of solutions....thanks and great videos

[@asice716]

This video is insanely good. I have a nb Miata with P0455 code. Learn a lot about this code from you!

[@1995jug]

Good fix Eric, glad you brought up the issue on notifications mine started working after that video.

[@WayneYoung-fx4vn]

Thanks dude, you da man. You have helped me a lot.really appreciate your knowledge. If I could just afford that high dollar snap on tool and learn how to use it. Next I gotta figure out my speedometer not working ,changed the speed sensor in the rear of my dakota ,but that didn't do it either.

[@sheldonbryan5521]

Big help for me thanks. I have an 05 equinox with the same engine. I've had to change out the purge solenoid on it. Now I'm having the same issue on my daughters 04 pt cruiser touring edition. 🙈

[@jamiebaltazar]

Good job! You explained real good and described ecm codes!

[@ildarsalimov108]

Thank you for the detailed video. I have P0455 code and after I removed Purge valve I saw charcoal pieces coming out from the valve. What is the problem? Do I need to replace charcoal canister? Thanks,

[@baxrok2.]

Very useful information sir! Thanks for showing us how it's done!

[@kmartin5054]

An excellent video to diagnose evap problems.

[@samyz1660]

I wish you were closer so I can take my 2009 Mazda 3 to solve the mysterious evap problem. Took it to two mechanics without success. Impressive skills set.

[@JamesSmith-xs7sr]

Loved the screwdriver hammer treatment! Brute force works!

[@YH7R]

hello, just ran across your content i can say you are very thorough......i just subscribed thanks for content

[@govindagovindaji4662]

Thanks so much. My old lady self and 40 yr old daughter are going to try and fix this together. What is the name of the machine you are using to diagnose? I bet it is expensive as it doesn't just give you options of what might be wrong;, it seems to give you ways to use the process of elimination, too. (I'm referring to when you tried things and waited to hear or not hear a click). Am I correct in that~? Is it more advanced than those systems friends bring over to just read code~?

[@jmcenterprises9591]

I need one of those code scanners. Thanks Eric O for another great vid.

[@mariosanchez-sj9yv]

We learn something new every day

[@harleyadam4813]

Great diag! EVAP codes can be a real bear to track down sometimes.

[@RoadHeros610]

Dude you're awesome I have a 2008 Volkswagen Touareg I hope I have the same issues is that ..u out a good teacher and explain er

[@billmeyers9584]

Great video. Fighting the P1445 code with my 1998 Mustang Cobra...