Check Engine Light Due to Intake Manifold Vacuum Leaks on Pontiac Bonneville

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: (–)
Engine affected: 4.6L V8
2 model years affected: 2004, 2005
2 people reported this problem