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2001 Chevy Cavalier O2 Sensor Not Ready: Smog Failure Fix and OBD2 Code Resolution

Model: 2001 Chevy Cavalier Fault Code: P0135 Posted: 2016-03-03 12:18

I own a 2001 Chevrolet Cavalier that failed its smog inspection. I have already replaced both the upstream and downstream oxygen sensors, but my OBD2 system still shows 'O2 sensor not ready' errors. Despite the sensor replacements, the vehicle's readiness monitors remain inactive. I'm seeking advice on how to properly reset these monitors and ensure the O2 sensor readiness status is updated.

Related fault codes

P0135

Comments (3)

Anonymous 2016-03-03 12:46

Clear all diagnostic trouble codes (DTCs) using an OBD2 scanner, then perform a complete drive cycle under normal driving conditions to allow the vehicle's ECU to re-engage and verify the oxygen sensor readiness. This process helps reset the readiness monitors and may resolve the 'O2 not ready' issue. Refer to official OBD2 troubleshooting guides for detailed steps.

Anonymous 2016-03-03 12:50

Thanks — I'll try this tonight after clearing the codes and completing a full drive cycle under varied driving conditions.

Anonymous 2016-03-03 13:26

For more information on OBD2 readiness cycles, see: http://www.obd-codes.com/trouble_codes/...-cycle.php