continues to come on and the diagnostic test at Auto Zone said that an error has occurred due to the gas cap being left off. the only problem is that the gas cap is on so the diagnostic test is wrong. what is really causing the check engine light to come on??
If that is the case then the gas cap is not sealing, or holding pressure like it should. So unfortunately it would need to be replaced.
I took my jeep to advanced auto parts and i'll just tell you this; most of the people that work their know nothing when it comes to vehicles and parts.I had a battery replaced once and the guy broke the bolt when replacing the battery and rather than fixing it like he should he just told me to get my husband to put one on. Many times O riellys have given wrong parts. Had a diagostic test ran once and it read somthing completely different. What i would do is call the dealer or any good reliable mechanic and tell him what is going on and ask what could be causing that. I would still mention what the dianostic test read, that way they will have somthing to go on. Most of the time they can tell you without charging you. Call as many mechanics as you can. You can also go and buy another gas cap to see if that is what could be the problem, just keep your receipt just in case it isn't, that way you can return it. Just make sure you don't buy the same gas cap as before. Buy one that's different. Hope this helps.
The problem you have is LEAK in you fuel VAPOR system. That's the system that recovers your fuel VAPORS. Your fuel tank is sealed so most think the gas cap is the weak link. But if you look under your hood, you will see on you drivers side fender, That big black box. That's the charcoal canister. The fumes get pumped through that. LOOK at the hoses, coming off that, CLOSELY. ANY cracks in those hoses will cause a leak. ANY hoses that are knocked off will cause a leak. FOLLOW those hoses, there all real short, SEE where they connect to. ANY cracks in the hoses there will cause a leak. Believe me you will see a cracked hose or completely broken hose. CHECK them all in that area. Just replace any cracked ones or cut and shorten them.
