DTC P0133: Ho2S Circuit - Slow Response - Bank 1, Sensor 1: Description

WARNING: This page is about a different car, the 2002 Pontiac Firebird and 2002 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.

The Powertrain Control Module (PCM) continuously monitors the Heated Oxygen Sensor (HO2S) activity. The PCM counts the number of times that a rich to lean and a lean to rich response is indicated. Then, the PCM adds the amount of time to complete all transitions for a 100 second test period. With this information, an average time for each transition can be determined. If the average response time is too slow, this Diagnostic Trouble Code (DTC) will set. A lean to rich transition is indicated when the HO2S voltage changes from less than 300 mV to more than 600 mV. A rich to lean transition is indicated when the HO2S voltage changes from more than 600 mV to less than 300 mV. An HO2S that responds too slowly is likely to be faulty and should be replaced.