Oxygen Sensor: Testing and Inspection
Inspection Of Terminal Voltage For Front & Rear Heated Oxygen Sensor1. Warm up the engine to normal operating temperature.
2. Run engine at idle speed.
3. Connect a voltmeter between terminal 4 (BLK wire) and ground.
4. Increase and decrease engine speed quickly several times.
5. Verify that meter reading varies between 0-1.0V.
NOTE: Rear oxygen sensor voltage does not fluctuate as quickly as front oxygen sensor.
6.If not as specified, inspect:
- On-board Diagnostic System.
- System Inspection.
- Intake Manifold Vacuum.
- Fuel Line Pressure.
7. If all systems are normal, replace the heated oxygen sensor.
Inspection Of Front & Rear Heated Oxygen Sensor Heaters
1. Ensure ignition switch is OFF.
2. Disconnect heated oxygen sensor connector.
3. Connect ohmmeter between terminals 2 and 4 and measure resistance.
Specification: Approx. 6 Ohm (68 °F (20 °C))
4. If not as specified, replace heated oxygen sensor.
Tightening Torque: 22 - 36 lb.ft (30 - 49 Nm, 3 - 5 kg.m)
5. Reconnect heated oxygen sensor connector.