P0134 and P0132 O2 Sensor Faults - 2003 Pontiac Grand Am Diagnosis
I own a 2003 Pontiac Grand Am and am currently experiencing P0132 and P0134 diagnostic trouble codes, which indicate issues with the heated oxygen (O2) sensor. I recently replaced the O2 sensor, but the check engine light remains on. The vehicle shows no noticeable exhaust problems or performance issues, and there are no other related error codes. I'm seeking advice on possible causes and troubleshooting steps to resolve this issue.
Did you install an aftermarket O2 sensor or wire it yourself? Using a scan tool, check the O2 sensor voltage readings by intentionally adjusting the air-fuel mixture to rich conditions and observe voltage response. Are there any other diagnostic codes present? What are the actual sensor voltage values reported by your scanner? Is there any noticeable lean condition or exhaust-related symptoms?