Check Engine Light Due to Gas Cap or Catalytic Converter on Cadillac DeVille

Two likely causes for the Check Engine Light to illuminate would be a loose or worn gas cap or a faulty catalytic converter.

RepairPal Verified
Average mileage: 160,000 (160,000–160,000)
1 model year affected: 1998
2 people reported this problem
1 person shared problem details
1998 Cadillac DeVille160,000
I keep getting MIl Code P0440, and have repaired everything in evap system w/o curing this problem.
Related Items:
Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
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...
...old vacuum leak can develop from a variety of sources, often causing illumination of the Check Engine Light with codes P0171 & P0174 stored. Thorough diagnoses will be necessary to pinpoint th...

Related Content