i have a 94 xlt 4x4with 112k with a 302 in it the truck runs like a top. the check engine light doesnot come on until i drive the truck for approximately 10 mins or so and if i turn the truck off the light goes out again until i drive it for a few more mins i cant figure it out. i just got the truck and i didnt get a chance to get the code checked at autozone or anything but i was wondering if this is a common prob that can be an easy fix.
please advise

 

It could be dozens of things. You really need to pull the code(s) first.