Start problem

Only after refueling, my 2004 Cayenne (6cyl)is difficult to start. Otherwise, all is normal except for the check engine light. To start the car after fueling, the accelerator must be fully depressed. If not fully depressed, the engine just sputters. The dealer put it on the computer and said the gas cap was not tight enough. Two thousand miles later with conscious effort to to “click” the gas cap, the problem continues.

If the cap is removed without fueling, there is not problem. The sputtering only happens after fueling.

We get these types of posts here quite regularly.

The fault may or may not relate to a saturated charcoal canister. Have an automotive store like Autozone or some other pull the code again. If it refers to the EVAP system this may be the fault.

The dealer pulled the code and said it related to a loose gas cap? Perhaps that gas cap isn’t sealing properly.

Is the CEL still on?

The dealer turned-off the CEL. After the next fueling and difficult start, the CEL came on after 5-10 minutes.

Does the “P” code translate to "loose gas cap? or “evaporative emissions system faiure” For BMW you can test the evap system through a diagnostic test program (not a smoke test) only after car passes diagnostics do we conclude concern was only a loose gas cap.