Operation CHARM: Car repair manuals for everyone.

Oxygen Sensor: Testing and Inspection


Inspection of Terminal Voltage.
1. Warm up the engine to normal operating temperature and run it at idle.
2. Disconnect the oxygen sensor connector.




3. Connect a high internal resistance voltmeter (more than 40 k ohms) between the oxygen sensor terminal and ground.




4. Measure the voltage while increasing and decreasing the engine speed suddenly several times.




Specification