Cel... P0456... Help!!!

[oneovdabestyet]

code reads P0456

Evap emissions

control system leak

very small

** what experience do you guys have with this?? thanks in advance guys!

[plokm]

Could be anything...try clearing cel and see if you come back

[STONER]

Chances are its your N80 valve or maybe you didnt tighten your gas cap all the way. N80 is cheap though and easy to replace. You can clear it and see what happends. May take a while to come back or might come back in a drive cycle or two.

[oneovdabestyet]

i tried the gas cap... but replacing a gas cap why would one need to do that, gas caps go bad?

[CystmX]

i tried the gas cap... but replacing a gas cap why would one need to do that, gas caps go bad?

The seal on the gas cap can go bad, yes.

[clemsongt]

i tried the gas cap... but replacing a gas cap why would one need to do that, gas caps go bad?

While a gas cap seal can go bad, typically if a code is thrown and that's the culprit, the reason is the cap wasn't tightened enough.

[oneovdabestyet]

While a gas cap seal can go bad, typically if a code is thrown and that's the culprit, the reason is the cap wasn't tightened enough.

interesting... what do you guys recommend doing first? I'm having g a really hard time finding the N80 valve for our car, if someone can post a link, much appreciated...

thank you guys, a CEL in an audi is a frustrating way to start a day I'm sure you guys know what i mean!

[CystmX]

First is tighten up the gas cap and reset the code. If it doesn't come back on then your good to go. Now if it does then go ahead and replace your N80 valve. The N80 valve is to the right of your engine. Take the engine cover off and you should be able to see it. It has 1 hose on each side of it and a electrical connecter.

[oneovdabestyet]

First is tighten up the gas cap and reset the code. If it doesn't come back on then your good to go. Now if it does then go ahead and replace your N80 valve. The N80 valve is to the right of your engine. Take the engine cover off and you should be able to see it. It has 1 hose on each side of it and a electrical connecter.

reason I couldnt find the purge vale was because it is formally called a Vent Valve Vapor canister purge valve. GOD!! anyway by the clear the code do you mean just remove the negative charge from the battery?

[makav3li]

you could do that but its better to get it cleared from an obdII scanner or vag-com, autozone will scan and clear for free

[clemsongt]

you could do that but its better to get it cleared from an obdII scanner or vag-com, autozone will scan and clear for free

Actually autozone, advance, etc will NOT clear the code. They are specifically told not to due to liability issues. Now, that's not to say some of the guys won't do it, but they aren't supposed to.

[CharlesP2009]

Der Audi threw me this code today with a Check Engine Light. The two days prior I was getting the "Close Fuel Tank Cap!" message in my DIC after starting up in the morning. Both times the fuel cap message went away after tightening a click or two. I cleared the P0456 code with a scan tool and thus far it hasn't returned after 5 miles of driving.

So...now I have to figure out if my fuel cap is on the way out or do I really have a very small Evap system leak? Guess I'll wait a fuel days to continue monitoring before I start throwing parts at the problem. I've searched the forum and lots of folks with the fuel cap message have fueling issues, I have none whatsoever. The N80 is another common culprit and thankfully they're cheap to replace. The car seems to be running brilliantly otherwise.

Wanna know what's the most annoying thing? My warranty just ran out less than 2 weeks ago!!

[ag34]

l had same problem
first i replaced gas cap and light came back
than i replaced n80 valve its was gone
it was 20 $ or something like that
i replaced it myslef and l`m npt a handy guy
it took like 10 mins
if you need more info hit me up
good luck

[slvrb7]

charles p replace gas cap or you can do a temp fix and take the seal off flip it and put it back on but more then likely that is your issue.

[slvrb7]

there is actually a part number update of the caps and from what im aware of that was an issue with people is the caps not sealing like they should especially with age.

[CharlesP2009]

charles p replace gas cap or you can do a temp fix and take the seal off flip it and put it back on but more then likely that is your issue.

Unfortunately it does seem to be the N80 valve. The gas cap message has returned 2 or 3 times even though I tried flipping the seal and even treating the rubber with Einszett Gummi Pflege. I've also gotten 3 CELs. Cooler weather seems to be the catalyst in my case. If it's consistently warm the car is absolutely fine but if the temp dips below 50°F overnight I'll get either the fuel cap message or a CEL. Guess I'll have to fork over the $27 to my dealer for a purge valve...

[nedrager]

N80 fixed it for me, but I had CELs for very small and large leaks detected.

[Mc Suly]

n80 for me!