The other day I was driving down the highway and my gas cap light came on. I pulled over took the cap off and put it back on and that didn't make the light go away. I didn't think much of it and a couple days later my check engine light came on (I assume this is because of the other warning?). Ive gone thru 3 tanks of gas since then and my mpg's are the same and the truck doesn't seem to be running any differently.
Any ideas whats going on here and how to fix it?

 

Gas cap was either loose or has a bad seal. If you have a programmer you can clear the code (or take it to one of the autozones/napas/checkers and they can do it with their scan tools), if it stays off then the cap was probably just loose, if it comes back on you'll more than likely need a new cap.

 

If the light comes back on after you clear it it may be the cap has a bad seal or theres a leak somewhere else in the system....then you will need to get a pressure system check and a vacume check done.

 

cant you clear the code by just unhooking the battery for awile? thats what i always do and it works

 

Yeah you can do that but I think the thing is here he is ***-U-ME ing that the cel is related to the gas cap light, he don't know. If he had a tuner it would tell him exactly what was wrong, even better than the scanner tools they use at the parts stores.For example, I popped a cel for a 02 sensor the other day and the SC tuner told me which one it was. The scanner tools they use at the parts stores just say 02 sensor bad, not which one. I think he needs to find out what the code is he is throwing and if its related then the first thing I would do is buy a new gas cap. Always try the cheapest first. But if he can find out what the CEL is then it might expalin the problem more.

 

hi i just fix my 2008 nitro it has a solonid on the side of the battery wt 2 hoses one its on the bottom it was broke on the bottom its wy you gas cap ligt is on and also show evap small leak so chek those hoses its a hard plastic hoses i cut my an put flex hose hopole works for you

 

I would replace the gas cap first. Buy it from a dealer however. The aftermarket ones are crap, I've been down that road.

 

The gas cap code can only be cleared if you ran a Evap test first and if the test passes then you can clear the codes with a scanner.

 

Don't know what to tell you. The gas cap code went away a couple of starts after I replaced the cap. 2006 Mega Cab. It has not returned. No one cleared the codes.

 

I'm not always right. The Evap system may have perform its own test thru PCM and then turn the lamp off. But I'm sure you will have the stored code for 255 starts and then go away.