DTC P0133: Heated Oxygen Sensor No. 1 Circuit - Slow Response: Condition

DTC is set when time for Heated Oxygen Sensor No. 1 (HO2S-1) to change from lean to rich or from rich to lean is high (one cycle every 5 seconds). MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible cause is HO2S-1 malfunction.