Over the past 2 years I have had the check engine light come on 3 times, and each time, when checked, I was told the codes showed a loose/leaking cap. The local dealership has sold me 3 gas caps and each time within a month the light came back on. I have checked the cap and never found it loose, so I have ignored it for the last year. What else could cause this?
Thanks
Michael

 

The rule of thumb when tightening your gas cap is to make sure you give it at least 3 clicks. I think my last Chrysler car actually wrote the gas cap for 5 clicks.

If it's not the gas cap though, it's probably the evap system. The evap canister could be cracked, or a hose loose/cracked. I don't recall where it is on the truck though. That would throw the same code as a bad gas cap.

 

The "leaky gas cap" CEL is REALLY a code for a leak in the Evaporator System. Yes, it's most commonly the cap BUT could be anything in the system from a failed hose clamp to a cracked hose to the canister itself.

I have a map of the entire Evap System in the FAQ section, use it and trace out the problem. If not the cap, it's often a failed hose clamp and/or split hose right at the canister. Chrysler uses the cheeziest clamps I've ever seen, btw...

 

yeah, most guys find the problem under the truck like hammer says

 

Thanks to all thank responded, I will start checking tonight when I get home.
Michael

 

My 03 had the same problem and it ended up being in the evap system, It's been many years since so i cant remember the part but it wasnt anything crazy.

 

My truck had this issue when I bought it new from the dealer with 400 miles on it. Came on once they said gas cap, came on again a few days later and they said there was a short in the dashboard wiring causing it to read that the gas cap was off even though it wasn't and they replaced the whole gauge cluster. Hasn't been a problem since, have about 20K on the truck now.

Doubt this is your problem but just some food for thought since it was the answer to my gas cap problem.