Cadillac DeVille Problem Report

Cadillac DeVille Check Engine Light Due to Gas Cap Issue

(40 reports)

Illumination of the Check Engine Light can be caused by a loose or worn gas cap.

Code came up with very small vacuum leak in evaporator system or also Check Gas Cap. I originally fixed the problem by dabbing a small amount of grease on the rim of the gas filler neck. But after a year or so I finally figured out the problem. The gas cap is a poor design. I tore apart the gas cap and found out the seal that is really a like a rubber grommet does not contact the rim of the filler neck properly. I took a piece of single strand copper wire and wrapped it around the back side of the seal (side closest to the handle of the cap) forcing the seal closer to the rim side of the filler neck. Problem solved. RRH -
Dealer wanted $79.50 for a new cap. Autozone $12.00 -
I got the warning. I took the gas cap off, cleaned it and applied some light silicon lubricant and the problem hasn't come back in a couple of years now. I did NOT replace the cap... just cleaned it. -
I have replaced the gas cap twice without eliminating the problem -
Not fixed, needs new gas cap, needs so much stuff, this is small. -
Service engine light on and evap code. Both (99,400 and 14,300)times resolved with new cap. Seems like cap should last longer. -
check gas cap comes on on the dash replaced cap 3 times still comes on have reset computer everytime -
appears that after it rains the Check Gas Cap sensor goes on.. Thinking it's a Sensor issue -
I replaced the gas cap and it is still and issues. I suspect there is a vacuum leak somewhere around the gas tank. -
Tightened gas cap and the light eventually went off. -
Problem not yet resolved. Will probably have to replace cap -
had to buy new fuel cap. then had to wait two days for sensor to register the new fuel had been installed before light went off. -
replaced cap multiple times from dealer. finally they must have felt sorry for me and told me to clean the cap really well...toothbrush & water...dry well with lint free cloth. It worked!!! have to do about every six months as error codes starts again. Still doing @ 102,000 miles...looks like they would have fixed this by now!!!!! -
Check Gas Cap displayed on 'info'. Tried tightening cap several times, light came back as soon as I started the engine. Saw on another forum that the cap may need replacing...will attempt that as the first option. -
Replaced cap. -
Happens by accident (my wife or kids) all the time...always make sure cap is tight when you are done filling the tank. -
Related Items:
check engine light on code po443 evap emission system purge vent soleniod circuit condition. wh...
replaced evap soleniod near gas tank and the one on the intake also replaced gas cap. cleared...
An intake manifold vacuum leak can develop from a variety of sources, often causing illuminatio...
Two likely causes for the Check Engine Light to illuminate would be a loose or worn gas cap or...
the car quit had to replace the whole fuel pump. since then the service engine light is on. i h...