Check Fuel cap
My truck displayed the Check Fuel Cap light, and then the check engine light came on. I have now put three new gas caps on and the same thing keeps happening. I have been working with a mechanic to get this problem solved, so I can get the truck smogged. We have checked all the fuel lines and hoses, and they all look good. It also takes over 80 miles of driving for the codes to re-set after clearing the dash lights, and before the codes are re-set the dash lights are on again. Anybody have a suggestion as to what is causing this problem?