why is my engine burning too much gas?
burning too much! on 1990 Cadillac DeVille
There could be any number of reasons your 1991 Cadillac DeVille is burning to much gas. Leaking or faulty fuel injector(s), leaking fuel pressure regulator, faulty O2 sensor to name a few, The first steps would be a complete inspection of the fuel system including a fuel pressure test. Also, checking engine control module for fault codes should be done.