Check Engine Light
Chevy Cheyenne
1995-2005 Chevy Cavaliers

Why would the service engine soon light come on after filling up the gas tank on a cold morning?



User Avatar
Wiki User

go check your gas cap and make sure it is on tight. Anytime you get a check engine light on after fueling, this normally means you didn't get the gas cap on. Make sure you click it the required number of times if that is how yours works. Also, if you leave the engine running while filling up you are going to get a service engine soon light on. Disconnect the battery and leave it disconnected for a couple hours to clear the computer, then hook the battery back up and the service engine light will be off. If it comes back on take it into Auto Zone, they will read the trouble code for free and tell you what triggered it.