Yup, I'm with Ranger... The only thing I would add is that some cars have had minor accidents and cracked the canister. If you can see the whole thing, check the canister itself for structural cracks as well as all the plastic lines going into it. If absolutely everything has been checked and nothing else makes sense, there is a one-way valve on the top of the canister that can go bad. Though it would be a rare occurrence, it could happen. Not sure if just that valve can be replaced or not. It might be a new canister. The car will run just fine with this problem, but your SES light will probably stay on until it's fixed, and you won't pass an emissions inspection if you need one.Ranger said:No, the EVAP system takes gas vapors from the tank, stores them in a charcoal canister when the engine is shut down and burns them when running. It is part of the emission control system (gas vapors in the air, ozone, yada yada yada). The first thing to check is the gas cap. If it is loose or not sealing properly it will trigger a DTC. There is also an EVAP purge valve and control solenoid, probably on the rear cam cover that controls the system. Check all the vacuum hoses and electrical connections.