I have a 1999 Jeep Cherokee and the check engine light has come on. It seems to be related to the fuel cap. How do I verify this and then keep this from happening?:banghead: The light goes off when I have a full tank then comes back on when I drive it a little.

Buy a new cap for $15..

You can pull the code by going to a parts shop...

I just purchased a new one myself..a locking one to prevent gasoline theft..