Gave us a code of "P0455"?

ANONYMOUS

MEMBER
2006 GMC SIERRA
60,000 MILES

HI my partners truck came on this morning with the "check engine light", we went to pep boys, the guy did some scan thing and gave us a code of "P0455" n told us to start by getting a new gas cap n that shuld fix it, well unfortunately they didnt hav the one we needed so we went to auto zone got it, n put it on, started truck and the check engine light still is on? What could this be? Its a 2006 gmc sierra.

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

The code:
P0455: Evaporative Emission (EVAP) System Large Leak Detected.

This code gets triggered when there is a leak detected with in the fuel tank and its components for emission. It could be a gas cap, but this larger leak typically is for a stuck open vent valve for the vapor canister or could be a broken hose.
Also keep in mind that the engine light must be reset after the issue is taken care of. Otherwise, the light could stay illuminated.

https://youtu.be/ahK_eucFi-k

I have attached the diagnostics for the code P0455 below. This can determine what is the reason for the check engine light.

Please let me know of any questions.
Thank you.

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