← Back to list

2002 Buick Centry Check Engine Light Codes 0131, 0135, 0171 - Solutions and Diagnosis

Model: 2002 Buick Century Fault Code: P0131 Posted: 2006-09-20 14:24

Hi, I recently purchased a 2002 Buick Centry from my father. The vehicle previously had its catalytic converter (cat) and oxygen (O2) sensors replaced before the issue arose. Currently, I'm seeing persistent OBD-II diagnostic codes: 0131, 0135, and 0171. After replacing the O2 sensor and resetting the system, the check engine light initially turned off but returns after parking and restarting the vehicle. The exhaust emits a significant amount of black smoke and has a strong rotten egg smell. The engine has accumulated approximately 121,000 miles. I'm wondering whether the O2 sensor should be replaced after the catalytic converter or if there's another underlying issue. Any advice on how to properly diagnose this problem would be greatly appreciated.

Related fault codes
P0131P0135P0171
Comments (6)
Anonymous 2006-09-20 16:06

The Mass Airflow (MAF) sensor might be dirty or malfunctioning, leading to incorrect airflow readings. The recently installed catalytic converter could still be contributing to the issue, especially since O2 sensors weren't replaced. Depending on the engine configuration, a vacuum leak—possibly from intake gaskets—is likely causing the 0171 code. Additionally, wiring issues with the O2 sensors should not be overlooked. More details about the repair history, such as when and why the work was done, would help pinpoint the root cause.

Anonymous 2006-09-21 11:41

The engine is a 3.1L V6 (3100). I cleaned the MAF sensor this morning, changed the spark plugs, and briefly disconnected the MAF cable for 10 minutes—yet the check engine light still came back on after restarting. The vehicle runs with power but continues to trigger the code. To determine whether it's a vacuum leak, catalytic converter issue, or MAF sensor failure, I need a systematic diagnostic approach. Initially, during emissions testing, the system reported codes 0102, 0131, and 0135. Both O2 sensors were replaced—one at AutoZone and one at Advance Auto Parts. Any further suggestions would be helpful.

Anonymous 2006-09-21 11:41

The engine is a 3.1L (3100). I cleaned the MAF sensor this morning, changed the spark plugs, and briefly disconnected the MAF cable for 10 minutes—yet the check engine light still returned after restarting. The vehicle runs normally but continues to trigger the code. How can I properly determine whether the issue stems from intake gaskets, the catalytic converter, or the MAF sensor?

Anonymous 2006-09-23 12:13

Charles wrote: The engine is a 3.1L (3100). I cleaned the MAF sensor this morning, changed the spark plugs, and briefly disconnected the MAF cable for 10 minutes—yet the check engine light still came back on after restarting. The vehicle runs with power but continues to trigger the code. To determine whether it's a vacuum leak, catalytic converter issue, or MAF sensor failure, I need a systematic diagnostic approach. Initially, during emissions testing, the system reported codes 0102, 0131, and 0135. Both O2 sensors were replaced—one at AutoZone and one at Advance Auto Parts. Any further suggestions would be helpful.

Anonymous 2006-09-23 12:13

Charles wrote: The engine is a 3.1L (3100). I cleaned the MAF sensor this morning, changed the spark plugs, and briefly disconnected the MAF cable for 10 minutes—yet the check engine light still came back on after restarting. The vehicle runs with power but continues to trigger the code. How can I properly determine whether the issue stems from intake gaskets, the catalytic converter, or the MAF sensor?

Anonymous 2006-09-23 14:31

Always check the wiring connections to the O2 sensors before replacing parts—don't just replace components without verifying faults first.