Evap Diagnostic Code???

Had my 02 Dodge Grand Caravan Sport diagnosed at Aamco. Evap code came back, indicating the gas cap may not be on tight enough. (this was the case about 3 weeks ago when the engine light came on, Aamco diagnosed, screw the cap on tighter, and the light went off) This time it's definitely not the gas cap. I even bought a new one, and filled up the van completely (in case it was just a bad tank of gas) and still that wretched light is there. I was referred to my local Dodge dealer for a "evap diagnostic machine" to better diagnose the problem, to the tune of $85.00. I have not done this yet. Any advice or suggestions on things to try beforehand? My husband is too busy at work to help.

Did they tell you what the code was? If not there may be a problem with purge solenoid located under the hood. Costs $30 from a dealer and can be replaced in less than 30 minutes. If this does not work then check all the hoses going to the charcoal canister that is located under the driver side of the van. If one is broken or cracked replace it and it should cure the problem. Take the van to autozone and get the code from them, it's free and they may even tell you how to fix it. If they can't help you then post the code here and someone will help you.

Thank You for your help. Aamco didn't give me the code today, but they may have given it to my husband a few weeks ago when we took the van there. I'll check with him. I'll take your advice and go to Auto Zone and get that all important code and post again with it. I'll also see if I can get someone to check out the other possibilites you mentioned. Thanks again for your help. It's really frustrating being a female with car problems, you never know whether or not the mechanic is taking advantage. :o)

My 2002 Grand Caravan saga is similiar. I tried a gas cap too! I think my code was 442, "Very small leak". That description doesn't narrow it down enough for me!! I'll check the hoses at the canister tommorrow.....could the purge solenoid cause my symptom as well? If I find anything exciting I'll post it here!!

Usually, when a P0442 code shows up, it has to do w/ the NVLD pump which pumps fumes from the fuel tank to the charcoal canister under your hood. If the system does not detect the right pressure, it will set a light; sometimes it'll illuminate all the time, sometimes, it's intermittent. It won't cause any serious driveability issues, just an annoying light. Those lines get kinked and bent b/c they sit so close to the body of the van and as you hit a bump in the road, could cause a line to become cracked causing the code that you are having now.