I have a TJ 2003 with a 4L six and about every 4 fills the check engine light comes on and 1 or 2 days later it goes out!
Its new to me and it does not stop the jeep from working right , just drives me nuts as I drive it.

Randy

 

I had 2000 TJ until last summer and i had similar problem. Took it to corner mechanic and he said its oxygen sensor. some cleaning of oil around and problem stopped. Not sure was it really because of that but engine light went away..'

 

If you loosen the cap with the motor running it will set a code. if the cap is not sealing it will set a code.

 

Try replacing your gas cap.

 

The check engine light comes on for over a thousand reasons,
trying to diagnose it without pulling the codes is foolish at best,
have the engine codes read and post up the numbers here to start...

Billy

 

Yes and the light just went out on its own again 48 hr same as last time and no codes set ????

 

Engine error codes are stored in the computer,
even if the check engine light goes out,
please hook up a code reader and see if you can get the error codes.
Do not assume because the check engine light has gone out, everything is fine.

Billy

 

Princess Auto Code Reader,

AutoLink® AL301 OBDII & CAN Code Reader | Princess Auto

listed at $59. they are sometimes on sale for $39.
A very good investment for any jeep owner...

Billy

 

and if you're going to leave negative props because you didn't get the answer you were seeking,
go fawk a duck...

Billy

 

and if you're going to leave negative props because you didn't get the answer you were seeking,
go fawk a duck...

Billy

Not sure what you mean negative props??? and I am getting some great answers just my stuped jeep did not leave a code . And I will have to go check out the reader you told me about thanks
Randy