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1998 Pontiac Grand Prix 3.8L P0108 Code: Troubleshooting Guide for MAP Sensor Too High

Model: 98 Grand Prix Fault Code: P0108 Posted: 2007-12-09 18:42

I own a 1998 Pontiac Grand Prix with the 3.8L engine, currently at 150,000 miles. The car runs smoothly and has no noticeable performance issues. However, I've recently cleared the P0108 diagnostic trouble code (DTC) for the second time in just two weeks. This code indicates a manifold absolute pressure (MAP) sensor reading that is too high. There are no other symptoms such as stalling, poor acceleration, or rough idling. Given this recurring issue, what should I do to properly diagnose and resolve the P0108 code?

Related fault codes

P0108

Comments (3)

Anonymous 2007-12-10 10:48

Start by checking the circuit wiring diagram for the MAP sensor and inspecting all connections for corrosion or loose wires. A faulty connection can cause incorrect readings. Also, consider replacing the MAF (mass air flow) sensor as a potential contributing factor.

Anonymous 2007-12-10 11:40

Jeff Compton wrote: With a circuit wiring diagram or a new MAF sensor. How does the MAF sensor relate to manifold pressure? I thought the MAF only measures incoming air volume, not directly affect MAP readings?

Anonymous 2007-12-10 12:00

Sorry for the typo — it's MAP, not MAF. If I recall correctly on this engine model, a blown seal around the PCV valve can cause incorrect MAP sensor readings and trigger the P0108 code.