The exhaust gas oxygen sensor supplies the electronic control assembly with a signal which indicates either a rich or lean mixture condition, during the engine operation.
Removal & Installation
- Disconnect the electrical connector from the sensor.
- Remove the oxygen sensor.
Installation is the reverse of the removal procedure.
NOTEApply anti-seize compound to the threaded portion of the sensor, prior to installation. Never apply anti-seize compound to the protector of the sensor.
Perform a visual inspection of the sensor as follows:
- If the sensor tip has a black/sooty deposit, this may indicate a rich fuel mixture.
- If the sensor tip has a white, gritty deposit, this may indicate an internal coolant leak.
- If the sensor tip has a brown deposit, this could indicate excessive oil consumption.
- Warm the engine until the coolant temperature reaches operating temperature.
- Run the engine at idle speed.
- Connect a voltmeter between terminal 4 (blk) and ground.
- Increase and decrease the engine speed quickly several times.
Specification should be 0-1.0 volt.
NOTEThe rear sensor voltage does not fluctuate as quickly as the front sensor.
- If not as specified, inspect the on-board diagnostic system, exhaust system, intake manifold system and fuel line pressure.
- If all systems are normal, replace the sensor.
- To check the heater, be sure that the ignition switch is OFF.
- Disconnect the sensor connector from the wire harness, if not already done.
- On 1996-1997 vehicles connect an ohmmeter between terminals 1 and 3. Measure the resistance. Specification should be approximately 6 ohms at 68 degrees F.
- On 1998-2002 vehicles connect an ohmmeter between terminals 2 and 4. Measure the resistance. Specification should be approximately 5 ohms at 68 degrees F.
- If not as specified, replace the sensor.