Gas cap problem

[jimzim7]

I have reoccurring gas cap light come on then sets the check engine light off.

It's hot here and I don't get to drive the Jeep Wrangler 08 daily. But have changed the cap 4 times. It resets and turns off code but after a couple months of the new gas cap it sets the gas cap code again. I have tried Jeep caps and off brand with the same results. Any ideas?

 

[dwillys]

Make sure the rubber gasket on the cap doesn't have anything on it and it is perfectly clean. Make sure the mating filler neck surface is also clean. If this is good, you may want to put a small amount of grease all the way around the gas cap gasket to see if it seals that way.

 

[JPNinPA]

IIRC there is an evap line that can cause a similar fault. If anyone finds it before me please post it up.