Review on 🔒 ACDelco GT279 Fuel Tank Filler Cap - Genuine GM Original Equipment by Brent Porter

Fixed leak in evaporator system. P402 trouble code on GM vehicles. Suggest you do some tests before you just buy it. If you have an error code, take a small amount of oil and lubricate the o-ring in the gas cap. Reset the trouble code (SES or Service Engine will light up soon). Your engine computer will check for small leaks under certain conditions (fuel 1/4 to 3/4 and coolant temp below 120 and ambient temp above 40 but below 85 and throttle position below 50%). If you drive within a week of lubricating the o-ring and the error does not appear, then the problem is most likely with the gas cap. Buy one that fits your vehicle. It was perfect for my 2002 Pontiac Grand Prix.