Car Problem Reports
Cadillac DeVille Check Engine Light Due to Gas Cap or Catalytic Converter
Cadillac DeVille Problem
Model Year Affected: 1999
Average Mileage: 82,500 mi (55,000 mi - 110,000 mi)
Check engine light comes on, check gas cap warning. Mine is caused by a rotted gas overflow line. Seems that it has rotted so bad that when I top off the gas tank, it started overflowing to the ground. It is also causing a miss in my engine when accelerating (not getting full power due to fuel pressure). Have not repaired yet but have found the fuel filler neck on eBay for $70.00. I was told you can cut off the bad section of the overflow, and clamp on a 3/4 ID fuel line. I am certain this would work, however if the line is that rotted I think I will install a new one for the $70 price.
Visitor, 1999 Cadillac DeVille, 55,000 mi
check engine light comes on when gas reading reaches 8, 10 and 11 gals. Had new catalytic converter put on also o2 sensor thought everything would be alright, but when gas reading came down to 11 gals. check engine light came on again, had it check by computer and got the same reading as befor bad 02 sensor.