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.
Check Engine Light Due to Intake Manifold Vacuum Leaks on Cadillac Seville
Average mileage: 76,000 (76,000–76,000)
12 people reported this problem
1 person shared problem details
1998 Cadillac Seville76,000Visitor
engine needs service soon
The "check engine" light comes on and sometimes goes off. Lately it has been staying on. The...
The EGR control solenoid or EGR valve may fail causing the Check Engine Light to illuminate.
The crankshaft position sensor may fail causing the engine to stall intermittently, the Check E...
The EGR valve may stick open, causing a rough idle and/or the Check Engine Light to illuminate.
Illumination of the Check Engine Light may be the result of a loose or worn gas cap.