Circuit Description
WARNING: This page is about a different car, the 2002 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
Heated oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. ECM uses input signal to determine fuel injection system operation. Heated oxygen sensors include a heater. DTC is set when ECM detects a response time of 1.1 second or more from heated oxygen sensor to change from rich to lean, or lean to rich when engine is warm and idling. Possible causes are:
- Open or short in heated oxygen sensor circuit.
- Defective heated oxygen sensor No. 1.
- Leaking air intake system.
- Fuel pressure problem.
- Faulty fuel injector.
- Faulty ECM.