Oxygen Sensor: Testing and Inspection

Heated Oxygen Sensor:

ON-VEHICLE INSPECTION

1. Warm engine to operating temperature.
2. Unplug sensor connector. Measure voltage at terminal A.

IDLE: Below 1.0V
ACCELERATING: 0.5 - 1.0V
DECELERATING: 0 - 0.4V

3. If not as specified, check intake air system, fuel system, and run on-board diagnosis test.
5. If no problems are detected, replace sensor.

HEATER RESISTANCE CHECK

1. Unplug sensor connector. Measure resistance between terminals C and D. It should be approximately 13 Ohms @ 68°F (20°C).
2. If not as specified, replace sensor.