Pontiac Repair: 2004 pontaic grand prix, pontaic grand prix, vent valve

Question
i cant pass emission because im showing code p0455 and my check gas cap light is on

Answer
Hi ther:

that codes can be a bad/loose gas cap. Not very likley unless the seal is ripped or torn on the cap or the wratchet will not allow you to tighten the cap fully. more then likely the issue is with the evap. canister vent valve. That is loacted under the car up by the gast tank filler pipe that is a VERY common issue on that model and year car. good luck :-)