Thread: Trouble code P0455

2004 grand prix gt just failed emissions because of this:

Trouble codes present
P0455 EVAP control system leak detected (gross leak)

Could this be from the ongoing gas cap light? Probably another sensor? Help soon or PONTIAC

After some researching I came up with either the gas cap or vent solenoid valve. Anyone ever replace this or any how to's on it.

Tried three different ones already, gas cap light stays on. I've never had a gas cap "go bad" before, why should it, it's a gas cap.

I've got this same problem. It's been ongoing for a little over a year. I've replaced the gas cap but no such luck. The code keeps coming back. Where is the vent valve solenoid? I've done it on my truck but that was right out in the open under the bed. Anyone have an idea where it is so I can change it?

had the same with my 02 gt.....a new gas cap and reset the code...stay cleared for an hour but i had to replace the evap .....remove or drop the inner liner from the back wheel well and it right there...reset the codes after.....same thing on my 05 silverado....159.00 for a new one but we used one for a surburban...49.00 plus a small piece of hose

Yeah I had to get the updated one for my 99 sierra, alot more money for the same piece as stock with a small length of heater hose included so you can put in spot with less dust. Stupid.

We're talking about the canister purge valve?