P0455 and P0456: Potential Help
I’ve been getting this P0456 ever since getting the car 3 years ago now, it would come on and go off on its own, so I kept ignoring it. No other codes. Every once in a while, P0456 would also show up. Now they’ve been consistently on all the time.
I know the services are unrelated but I’ve done a lot of possible maintenance since owning, including plugs, coils, OEM rear suspension rebuild, coolant flush, then another one when I did the gallery gaskets, timing chain and tensioner, water pump, timing cover gaskets, most being during the water pump replacement given accessibility. Never tended to this CEL cause it doesn’t seem to affect its driveability other than gas (I’ve been getting consistently 14.5mpg but I also drive with a very heavy foot as this is not my usual daily, only currently for the last 6 months while I repair my actual daily which had an accident.
I’m just looking for some pointers to resolve this CEL. Should I start with a new gas cap? My current one has a large silver colored ring around the gasket, so I think the seal is bad given it should be all the same gasket color but it looks good other than being silverish. Actually I do remember having replaced the EVAP valve that mounts directly to the back of the engine at the top, towards the firewall. That had solved the issue for about 6-8 months before it came back. Considering the charcoal canister may need to be replaced, but I am not sure if it’s covered up by my exhaust as it’s an Invidia Gemini. Is there anything else I’m missing that it could be? I’ll obviously be starting with the cheaper solutions like a gas cap first