How to Change the Oxygen Sensor Near the Catalytic Converter

Typical automotive oxygen sensor.

Depending on your particular vehicle model, there might be one or two oxygen sensors near the catalytic converter, one on each end of the unit. On some models, one of the sensors might be installed on the exhaust manifold or very close to it. Usually, you need to raise your vehicle to gain access to the one closest to the catalytic converter. But either sensor may be replaced using the same procedure described in the next steps.

Things You'll Need

• Floor jack
• Two jack stands
• Wrench set
• Ratchet and socket
• Box-end wrench
• Oxygen sensor socket
• Anti-seize compound
• Oxygen sensor gasket if necessary

Instructions

Removing the Oxygen Sensor

1. Start the engine and let it idle for about three minutes. This will allow the engine to reach operating temperature and make oxygen sensor removal much easier without damaging the threads on the exhaust pipe.

2. Raise the front of the vehicle and safely support it on two jack stands.

3. Unplug the oxygen sensor electrical connector from its harness by pressing the lock tab on the plastic connector.

4. Unscrew the two sensor mounting bolts from the sensor flange using a wrench or ratchet and socket. If your vehicle model does not use the flange type sensor, use a box-end wrench or an oxygen sensor socket and a ratchet to unscrew the sensor from the exhaust pipe.

5. Remove the sensor from the vehicle and discard the gasket if equipped.

Installing the Oxygen Sensor

1. Apply a light coat of anti-seize compound to the threads of the sensor mounting bolts or the threads on the unit, depending on which type of sensor your vehicle uses.

2. Set the sensor in place along with a new gasket, if equipped, and start the two mounting bolts or unit into the exhaust pipe by hand to avoid damage to the threads.

3. Tighten the two mounting bolts using a wrench or ratchet and socket if you have a flange type sensor. Otherwise, use the box-end wrench or ratchet and sensor socket.

4. Plug the oxygen sensor electrical connector.

5. Lower the vehicle.

Tips & Warnings

• It only takes a few minutes for the exhaust system and related components in your vehicle to reach very high temperatures. Whenever working under these conditions on your car, use caution to avoid skin burns and other injuries.