DTC P0133-00: O2-Sensor Circuit Slow Response (Bank 1/Sensor 1): General Description

In order to control emissions of the CO, HC and NOx components of the exhaust gas, Heated Oxygen Sensor (HO2S), mounted on the front side and rear side of catalytic converter, detects the oxygen content in the exhaust gas. The front Heated Oxygen Sensor (HO2S) Signal is used to control air/fuel ratio (closed loop fuel control) and the rear Heated Oxygen Sensor (HO2S) Signal is used to monitor front Heated Oxygen Sensor (HO2S) and catalyst for proper operation. The Heated Oxygen Sensor (HO2S) requires a minimum temperature to operate properly and provide a closed loop fuel control system. The Heated Oxygen Sensor (HO2S) contains the heater element to reduce its warming-up time and ensure its performance during all driving conditions. The oxygen sensor generates a voltage that indicates the difference between the oxygen content of the exhaust stream and the oxygen content of ambient air. When the exhaust stream is "rich," there is more oxygen in the ambient air than in the exhaust stream, so the voltage will be higher.