Topic: EVAP PO455 emission control system leak large? What should I do?

[WWI Flying Ace]

OK, so on the way to work today, the check engine light came on…yikes.

The car is a 2007 GXP with a Fujita CAI that has been on for a year with no problems, MBRB exhaust that has been on for 4 months with no problems, and the GMPP tune that was done about 9 months ago with no problems.  All these were done by a great dealer that is Solstice savvy. 

I went to the auto parts store at lunch and they have a reader they let you borrow to read the code.  I did so, and it said that there were 2 codes: the first was “EVAP PO455 emission control system leak large”, and the second was the same thing, only it had a state of “pending”. 

I need to clean the K&N filter, it was supposed to be in May but I will do it now.  Got the cleaner kit.  However…does anyone know if the filter can cause that error?  Are there other causes for an EVAP PO455  error that anyone knows of?  Do I just need to take it to the dealer?

Thanks in advance…Any information you guys can provide is very much appreciated. 

[Uranium-238]

I've been getting that and another evap leak code off and on since January. My solution has been to ignore them, as I feel that emissions systems are a waste.

Now that the weather is nice and I've got the top down, I have been noticing that the cockpit smells like fuel, and it never did before.

I've got a stock engine apart from a K&N filter.

[KWhale]

Ace - The P0455 code can be caused by a few things.  I've been researching this for that exact same code on my Durango, and here's what I've learned so far.

#1) - Make sure the gas cap is on properly.  If it is, then the cheapest fix of all for this code is a new gas cap.
#2) - If you are the kind of person who squeezes every drop into the tank that you possibly can when you fill up, stop doing that.  The overflow fuel is getting into the evap lines and can cause you problems.
#3) - there is a either a hose off, or a hose with a crack or hole in it.  This is the second most likely cause, and unless you have the ability to check out all the hoses yourself, it could be the biggest waste of money solution.

I have been living with the P0455 CEL on my Durango dash for about 1 year now.  I did replace the gas cap, I am not an over-filler, and I did trace all the hoses I could find.  Several hoses were old and weathered and perhaps cracked but I could not find a specific leak anywhere, and all were attached where they should have been.  In my case the entire vehicle is worth maybe $4k, I'm not going to throw hundreds of diagnostic dollars at what is essentially a moronic California (no offense GJ) emission standard.  If the light really starts to bother you, a little piece of electrical tape should fix that up

[Critterman]

Not putting on the gas cap properly after filling up is the most common cause of this code.

[DeepBlueGXP]

I had the same code and it was the gas tank pressure valve stuck open.

[chuckdoc]

Had this code also and fixed with a replacement gas cap

[WWI Flying Ace]

Thanks for all the answers guys.  OK, so I cleaned the K&N, and the code is still there, and I have filled it a couple times so it isn't an improperly applied gas cap...but it looks like the next thing may be replacing the gas cap.  Is that a warranty thing?  If so I think I might just live with this till the next oil change...

[KWhale]

Holy Cow WWI!  If you are still under warranty you're golden!  I assumed you were not under warranty still when I suggested that it's too expensive to diagnose if the easy answers don't fix it.  If you're under warrant, bring it in and let the dealership waste all the time to figure out what it is!

PS - That's why most of us have our car details in the My Ride part of our profiles....everyone trying to help you will know what car/year you have.

[WWI Flying Ace]

No worries.  I gave the details in the original post but didn't say specifically I was under waranty...but I want to know anyway, for the days in the future when I'm not...so I still would have asked the question so I can learn.     For example, I now know that I can live with this one until my next oil change and not have to make a special trip, which makes my life a lot better because getting time off to go to the dealer is a P.I.T.A.

Thanks again for all the assistance...I'll let you know what the dealer says...and I'll update my "My Ride" stuff too...I didn't know about that section.

[smartin]

I think I might need a new gas cap on mine, too.

[KWhale]

I think I might need a new gas cap on mine, too.

It really is the cheapest attempt at fixing the p0455 codes....assuming you're out of warranty!! lol

[smartin]

I'm so far out of warranty, it's not even funny!

[WWI Flying Ace]

Got it back from the dealer...was...the gas cap. 
No more Check Engine Light.

[Kelu]

  

[KWhale]

Right on!  The only warning now is this......When you clear the P0455 code, it can take a few days to return.  In the case of my Durango, it was gone most of the winter and didn't return again until we got above 75F one day.  I cleared it again, and it came back after about 250 miles.  So not to jinx you or anything  but I wouldn't consider it fixed until you've run for a couple of tanks of gas and had some hot driving days. 

[scanner]

Wow, I had no idea there were so many questions about this. P0455 is almost always related to the fuel cap to tank filler neck interface.   If it something else you have a large leak, most are easy fixes related only to the EVAP system. Either way the on board diagnostic system has determined that there is potential to give up fuel to evaporation and pollute the atmosphere. This test is only run under very strict conditions, too much or too little fuel and no test, too hot or too cold and not test, and so on.  It can weeks between tests.  P0455 is vehicle emission system related - read the warranty you likely have 5/50.  The regulators don't like mobile emitters.