Cadillac DeVille Problem Report
Cadillac DeVille Check Engine Light Due to Intake Manifold Vacuum Leaks
An intake manifold 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 the cause in order to make the correct repairs. A "smoke" machine is often used to isolate the cause of difficult to find vacuum leaks.
Diagnostic scan check - found engine misfire due to Intake Manifold Cracked and Leaking.
No work performed at this time. - MMB1968
check engine light comes on while driving - vandy
I have a 98 Cadillac Deville with a Northstar motor. It has been running hot. I changed the thermostat, and water pump but it is still running hot. My check engine light is on and these are the cod...
The EGR control solenoid or EGR valve may fail causing the Check Engine Light to illuminate.