1st CEL P0456

[S4Phantom]

Hey guys. So I got my first check engine light in my 2011 S4. Its P0456. I already have a gas cap coming from the dealer (I run the office in a repair shop so I get a good discount) but I just wanted to see if anyone has dealt with this code before and what their fix was. I asked the parts guy if they sell a lot of vent valves as I see that could also be the problem, and he said they did. Car is still under warranty so if the gas cap doesn't fix it I'll send it to the dealer as I looked up the labor time and apparently its a 5 hour job to change the vent valve. Anyone run into this problem, and what ended up being your fix. TIA

[xaser240]

I got that code a few months ago and dealer swapped my n80 purge valve. I was getting horrible gas mileage and that seemed to fix the problem. Just so happens that another check engine light popped on this morning so ill have to check that out later with my vagcom

[levigarrett]

I had to replace the vent valve in my A4 but I don't know what codes it was throwing. It was not however a 5 hour job on the A4. It was much less.

[xaser240]

Just scanned my car and its the same code. Vagcom says very small evap leak which is what happened last time and dealer changed the n80 purge valve. It also says it's running rich.

[S4Phantom]

Well I had cleared the light this morning and just went back out to check and found its a permanent code now but the light is off. Decided against the gas cap since its permanent that's a doubtful fix. Bringing it into the dealer Friday. This will be the first time they'll have to scan the car and now I'm nervous they're gonna find my tune and void my warranty. I knew getting the tune could cause them to void it so its something I'm prepared to have happen, but I just hope if it does TD1, the repair I need won't cost too much.

[S4Phantom]

I had to replace the vent valve in my A4 but I don't know what codes it was throwing. It was not however a 5 hour job on the A4. It was much less.

I looked it up on my system at work and I think it was a different valve it showed me and I didn't pay attention to that. It was the crankcase vent valve that takes 5 hours. Not the evap one

[Ryan_qttro]

Yea Crankcase vent valve on the S4 is below super charger, in engine valley.

[B8 S FOR]

Well I had cleared the light this morning and just went back out to check and found its a permanent code now but the light is off. Decided against the gas cap since its permanent that's a doubtful fix. Bringing it into the dealer Friday. This will be the first time they'll have to scan the car and now I'm nervous they're gonna find my tune and void my warranty. I knew getting the tune could cause them to void it so its something I'm prepared to have happen, but I just hope if it does TD1, the repair I need won't cost too much.

Good luck with that! Audi has become hell bent on TD1.

[S4Phantom]

Good luck with that! Audi has become hell bent on TD1.

Thanks. Yeah I just need to get it into my head that with what I CHOSE to put in my car would/could at some point void the warranty so it is what it is. Plus its up in 7 months anyway

[B8 S FOR]

Thanks. Yeah I just need to get it into my head that with what I CHOSE to put in my car would/could at some point void the warranty so it is what it is. Plus its up in 7 months anyway

My thoughts exactly...hell...as the saying goes... "you gotta pay to play!"

[S4Phantom]

My thoughts exactly...hell...as the saying goes... "you gotta pay to play!"

You are right. Well today is the day of reckoning lol. They are also checking my tranny because of my downshift clunk and making sure the software is up to date. So now Im worried that not only will the warranty go bye bye but that my tune is going to get wiped as well. 1st world problems

[S4Phantom]

Update for anyone who cares lol. Dealer got EVAP codes but everything checked out ok. They were able to get my tranny clunk to act up and are fixing that. Tranny software update and relearn going on now so hopefully that fixes it. Also found my sport diff seal to be leaking and fixed that. Everything under warranty so Im guessing I'm TD1 free for now since they would have had to get my ok to do these repairs out of pocket. Cars been there since Friday so hopefully I get her back today or tomorrow. Very happy with the service being provided by my dealer which is why I use them. Only thing that bothers me is if the EVAP has no "problem" but then it does again and I have to bring it back. Things could be much worse though so I'm hoping for the best.

[B8 S FOR]

Update for anyone who cares lol. Dealer got EVAP codes but everything checked out ok. They were able to get my tranny clunk to act up and are fixing that. Tranny software update and relearn going on now so hopefully that fixes it. Also found my sport diff seal to be leaking and fixed that. Everything under warranty so Im guessing I'm TD1 free for now since they would have had to get my ok to do these repairs out of pocket. Cars been there since Friday so hopefully I get her back today or tomorrow. Very happy with the service being provided by my dealer which is why I use them. Only thing that bothers me is if the EVAP has no "problem" but then it does again and I have to bring it back. Things could be much worse though so I'm hoping for the best.

Sounds good so far.... fingers crossed!

[vincenz0]

Sorry to revive an old thread, but I'm having this problem on my 2010 S4. I've cleared the code, tightened the gas cap, but it keeps coming back every 500 or so miles.

My car has about 83k on it. Is it possible that the gas cap is worn out and not sealing properly anymore? It's certainly been on and off a lot in 83k miles but I wouldn't think an item like that would fail.

Other than the cap, I guess check / replace that purge valve? I can probably do it myself -- what does the part cost?

[jl87]

My 2015 just had this issue taken care of at the dealership, there's a TSB for it. My paperwork is at home but I'll grab the info and update the post if you'd like?

[sirsycott]

My 2015 just had this issue taken care of at the dealership, there's a TSB for it. My paperwork is at home but I'll grab the info and update the post if you'd like?

please do , i've searched every thread for this code
my tuner shop also did a smoke test and couldn't find anything

i'm looking forward to finding out more details as every thread with this code no one ever responded back with a follow up to see if it was fixed and how

[jl87]

Here you go, this is for P0456:

[Rbb1485]

Update for anyone who cares lol. Dealer got EVAP codes but everything checked out ok. They were able to get my tranny clunk to act up and are fixing that. Tranny software update and relearn going on now so hopefully that fixes it. Also found my sport diff seal to be leaking and fixed that. Everything under warranty so Im guessing I'm TD1 free for now since they would have had to get my ok to do these repairs out of pocket. Cars been there since Friday so hopefully I get her back today or tomorrow. Very happy with the service being provided by my dealer which is why I use them. Only thing that bothers me is if the EVAP has no "problem" but then it does again and I have to bring it back. Things could be much worse though so I'm hoping for the best.

^What dealership are you using?