Operation CHARM: Car repair manuals for everyone.

Oxygen Sensor: Testing and Inspection





INSPECT HEATER RESISTANCE OF A/F SENSORS
a. Disconnect the A/F sensor connector.
b. Using an ohmmeter, measure the resistance between the terminals +B and HT.
Resistance:
0.8 - 1.4 (Ohm) at 20 °C (68 °F)
1.8 - 3.2 (Ohm) at 800 °C (1,472 °F)
If the resistance is not as specified, replace the sensor.

c. Reconnect the A/F sensor connector.





INSPECT HEATER RESISTANCE OF OXYGEN SENSOR
a. Disconnect the oxygen sensor connector.
b. Using an ohmmeter, measure the resistance between the terminals +B and HT
Resistance: 11 - 16 (Ohm) at 20 °C (68 °F)
If the resistance is not as specified, replace the sensor.

c. Reconnect the oxygen sensor connector.