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2002 Chevrolet Suburban 5.3L Engine P0151 Code - Check Engine Light Off but Inspection Failed

Model: 2002 chevrolet suburban Fault Code: P0151 Posted: 2018-01-01 23:17

I have replaced all components typically associated with a P0151 code, including the mass air flow sensor, oxygen sensors, and wiring harnesses. The check engine light is currently off, yet I am unable to pass vehicle inspection due to the persistent P0151 fault code. Despite multiple resets using a scan tool and battery disconnection, the issue remains. I suspect a wiring or signal circuit problem but need confirmation on how to properly diagnose it. Any advice or troubleshooting steps would be greatly appreciated.

Related fault codes

P0151

Comments (3)

Anonymous 2018-01-02 10:33

Even though the check engine light is off, the P0151 code may still be stored in the ECU memory. Try performing a complete reset using an OBD2 scan tool or by disconnecting the battery for at least 15 minutes. A P0151 code typically indicates one of the following: faulty oxygen sensor, short to voltage on the O2 signal circuit, high resistance or open in the O2 signal circuit. For detailed reference, see official OBD2 documentation on P0151.

Anonymous 2018-01-03 01:16

I've already attempted battery disconnection and scan tool resets seven times. I've replaced both mass air flow sensors and all oxygen sensors. At this point, the issue is most likely related to wiring—possibly a loose connection or damaged signal wire in the O2 sensor circuit.

Anonymous 2018-01-03 14:57

The O2 sensor sig wire should have a bias v of .45v from the PCM to the sensor and return. With sensor unplugged/ign on, check for .45v across the signal circuit. BBBind.com has schematic of O2 sensors. Loos like pins A&B sig circuit and C&D heater circuit ( 12v)