Oxygen Sensor: Testing and Inspection

COMPONENT INSPECTION
Front Heated Oxygen Sensor Heater




1. Check resistance between terminals (3) and (1).

Resistance: 2.3 - 4.3 Ohms at 25°C (77°F)

2. Check continuity between terminals (2) and (1), (3) and (2).

Continuity should not exist

3. If NG, replace the front heated oxygen sensor.



Rear Heated Oxygen Sensor Heater




1. Check resistance between terminals (1) and (4).

Resistance: 2.3 - 4.3 Ohms [at 25°C (77°F)]

2. Check continuity.

Terminal No. / Continuity
(2) and (1), (3), (4) / No
(3) and (1), (2), (4) / No

3. If NG, replace the rear heated oxygen sensor.

CAUTION: Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.