P0456

[2k16A6]

Tried a search but found very few hits mostly from 5+ years ago.

Anyone have a P0456 "Evap System - Very Small Leak" code? I've had it pop up 3 times now over the last month or so, used vcds to clear it each time and when it pops back up its always on startup. My first thought is to replace the gas cap and see if that fixes it but wanted to check in and see if anyone else has had this issue and got it fixed. There is a tsb for 2014-2015 Q7 with the 3.0T but I couldn't find anything for the C7/7.5 chassis.

Thanks in advance!

[Valpo A7]

Small Evap Leak on other cars usually means a loose gas cap. Pull your cap and wipe it down along with the filler neck and re-install. If it comes back then get a new cap. If it comes back again then you have to look deeper.

[PEM]

Small Evap Leak on other cars usually means a loose gas cap. Pull your cap and wipe it down along with the filler neck and re-install. If it comes back then get a new cap. If it comes back again then you have to look deeper.

This. Had this happen before and my gas cap was loose. Tightened it up, drove a little bit and the error went away.

[2k16A6]

Yeah the first thing I did was wipe down the cap and filler neck, but it keeps coming back. As I mentioned I may just start with replacing the gas cap and see if it comes back

[Burkeomatic]

If it is much past a gas cap it can be a pain to track it down with all the hoses and such that can have a little leak.

[2k16A6]

If it is much past a gas cap it can be a pain to track it down with all the hoses and such that can have a little leak.

haha yeah that's what I'm worried about.... Looked at the evap system in my erwin manual and there are hoses and other components running all over the place.

Ordered a new gas cap, should be here early next week so I'll keep my fingers crossed but I'm honestly not too confident that will do it. Time will tell

[2k16A6]

Well damn. New gas cap on late last week, P0456 came back this morning. Rather than checking and/or replacing random pieces of the evap system this may end up being something I have either the dealer or a more likely a good indy take care of for me.

[sepheroth86]

I have this same code. I have a new evap solenoid in the package.

I will be replacing it when I button up the cat gut, engine mount, PCV, t stat, waterpump, carbon clean. Hoping it gets rid of the CEL.

I will report back with results once the car is back together.

[WatchMeSpend]

I have this same code. I have a new evap solenoid in the package.

I will be replacing it when I button up the cat gut, engine mount, PCV, t stat, waterpump, carbon clean. Hoping it gets rid of the CEL.

I will report back with results once the car is back together.

What ended up happening with this? I got the code after filling up and thinking the gas cap isn't as tight as it should be. Looking for another gas cap, I see none for sale for MY 2016, but a gasket is $12. Cleared the code with HP Tuners (didn't know I could do that until I pressed a few buttons) and tightened the cap which for some reason felt better/firmer this time. Now I wait, but I'm positive it is the gas cap because I had the feeling it wasn't fitting as tight as it used to.