engine code P0455

that codes is a large leak detected in evaporator system which gas cap is part of. It should really be smoke tested to see where leak is, but it could be a bad solenoid or dirt in it not allowing it to close.

I have a 2007 Chevy Impala, and I just had the Code P0455 come up. What is the problem? It has about 120,000 miles on it and it has a 3.5 Litre V6. I just put a new gas cap on about a week ago, and the code P0455 still shows up, any ideas?

Hello,

DTC 0455 is that a leak has been detected in your vehicles Evaporative Emissions System(EVAP). Your EVAP system consists of a charcoal canister, vapor line going from your fuel tank to the canister, and lines to a solenoid or a EVAP Purge Flow sensor, and more hoses/lines going into the throttle body. Basically this is emission control system where fuel vapors are routed and stored in a charcoal canister until the vehicles Power-train Control Module(PCM)/Electronic Control Unit(ECU) a.k.a. computer decides it is a good time to introduce it into the throttle body to go into the combustion chambers and disposed of in the normal combustion cycle of the engine. Here is a link to a guide that should help you run down the problem:

https://www.2carpros.com/articles/evap-system-code-repair

Go through it and let us know what you find out. If you need further assistance, we can go from there.

Thanks,
Alex
2CarPros