Check Engine Light Due to Intake Manifold Vacuum Leaks on Cadillac DeVille

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.

RepairPal Verified
Average mileage: 132,940 (11,700–187,000)
Engines affected: 4.6L V8, 4.9L V8
7 model years affected: 1991, 1994, 1995, 1996, more1997, 1998, 1999
12 people reported this problem
5 people shared problem details
Diagnostic scan check - found engine misfire due to Intake Manifold Cracked and Leaking. No work performed at this time.
1999 Cadillac DeVille175,000
Cracked Intake Manifold was causing a misfire. It was Replaced with an Aftermarket Dorman intake. (Least expensive option)
Engine need servic cod#10174
check engine light comes on while driving
Related Items:
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...
check engine light on code po443 evap emission system purge vent soleniod circuit condition. wh...
the car quit had to replace the whole fuel pump. since then the service engine light is on. i h...
The EGR control solenoid or EGR valve may fail causing the Check Engine Light to illuminate.

Related Content