DTC P0133/P0153: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE Lexus LS III

Note. Bank No. 1 refers to bank that includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Sensor No. 1 refers to sensor closest to engine block.

Circuit Description

The oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. ECM uses this input signal to determine fuel injection system operation. Sensors include heater.

DTC P0133 is for bank No. 1, sensor No. 1. P0153 is for bank No. 2, sensor No. 1. DTC is set when engine is warmed up and idling if ECM detects a response time of 1.1 seconds or more for sensor to change from rich to lean, or lean to rich. Possible cause is

1. Open or short in oxygen sensor circuit.
2. Faulty heated oxygen sensor.
3. Air induction system fault.
4. Improper fuel system pressure.
5. Fuel injectors.
6. Faulty ECM.

Diagnostic Aids

Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.