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2003 Pontiac Grand Prix GT 3.8L P0101 Code: Engine Stalls After MAF and MAP Sensor Replacements

Model: 2003 pontiac grand prix gt 3.8l Fault Code: P0101 Posted: 2013-05-30 15:55

My 2003 Pontiac Grand Prix GT with a 3.8L engine has been experiencing intermittent stalling for the past four weeks—five times in total. The persistent fault code is P0101, indicating a problem with mass or volume air flow performance. I recently replaced both the MAF (Mass Air Flow) sensor two weeks ago and the MAP (Manifold Absolute Pressure) sensor last week. Despite these replacements, the engine continues to stall. When it stalls, the vehicle doesn't simply shut off—it drops to idle and then completely stops. Upon attempting to restart, the engine may fire briefly but fails to ignite properly. The fuel pump is confirmed to be functioning normally. I've cleared the P0101 code using a code reader, turned off the key, and re-started the vehicle—after which it runs smoothly until the next incident. This behavior suggests that the issue might not be purely sensor-related but could involve electrical faults or signal interference. Any insights into potential causes for this recurring stalling with P0101 on a 2003 Pontiac Grand Prix GT would be greatly appreciated.

Related fault codes

P0101

Comments (2)

Anonymous 2013-05-30 16:42

Stalling under these conditions is unusual. While MAF issues typically cause rough running or poor fuel economy, engine stalling points to a potential electrical problem—such as a shorted 12V supply or signal circuit. Are you referring to the older 3-wire MAF sensor? I'd like to confirm there are no aftermarket modifications like K&N filters installed. Have you inspected the wiring harness at the MAF sensor? Use a digital multimeter (DVOM) to test the wires: - Pink wire: should read 12V when key is on - Center black/white wire: should be grounded - Yellow wire: signal wire—this is critical for diagnostics Shake the harness gently to check for intermittent connections. Additionally, I'd like to know if your OBD-II scanner shows freeze frame data (such as P1XXX codes) and whether you used an AC Delco OEM part during sensor replacement. These details can help determine if the issue is software-related or hardware-based.

Anonymous 2013-08-05 15:38

I recently encountered the same P0101 issue on a 2003 Pontiac Silhouette with a 3.4L engine. After clearing the code, the vehicle started normally. To diagnose, I used a digital multimeter to probe the signal wire (LTgrn) from the MAP sensor while disconnecting the sensor and with the key ON but engine OFF. The reading was only 2.3V—well below normal—which indicated a faulty ECM (Engine Control Module). This suggests that even if sensors are replaced, an internal control module failure can mimic P0101 symptoms. This case highlights the importance of checking both sensor signals and the ECM's health when diagnosing intermittent stalling with P0101.