check eng light, gas cap

[bill6ft6]

just bought a 2002 conny this morning. has check eng light and codes for loose or cracked gas cap. I suspect a venting problem, what do you think?
bill

[Towncar]

Originally Posted by bill6ft6

just bought a 2002 conny this morning. has check eng light and codes for loose or cracked gas cap. I suspect a venting problem, what do you think?
bill

Check the gasket (seal) real closely.. make sure it's not bunched up, or not seating properly.

[bill6ft6]

just talked with the dealer. they say the check eng light is for a bent filler neck, and THAT THERE MIGHT BE OTHERS PROBLEMS BUT THE DIAGONISTICS WON'T PICK UP ANYTHING ELSE UNTIL THIS IS FIXED. i don't like that. min of $507 to fix. any suggestions?

bill

[Towncar]

I was assuming you've pulled some specific codes that show defective gas cap.

The cap shouldn't vent outward, but should allow air inward. The EVAP test is first started on the cap, it's pumped up with air pressure and fails the test if it leaks.

The remainder of the system is tested in the same manner, it's pumped up with pressure and fails when it leaks.

The OBDii System is the on board tester that lights the CEL when a fault is found. The CEL represents a fault code was found, and that code can be read using a scanner.

A bent/collapsed filler tube, unless it's broken its seal against the tank or cap , or cracked somehow, would not lose pressure. Of course this needs to be tested for leaks, and it certainly must be a PITA to fill the tank with a bent/collapsed tube, if that's the case.

Here's a couple examples of the system tests and component locations to help you make a decision:
http://www.troublecodes.net/articles..._Test_Kit.html
http://www.troublecodes.net/articles/intank.shtml