Oxygen Sensor (Upstream) Replacement

PROCEDURE



Removing the oxygen sensor from a cold engine may be extremely difficult due to thermal contraction of the exhaust manifold/pipe metal. To avoid the risk of damaging components, run the engine for a couple of minutes before removing the sensor and take care not to burn yourself on hot surfaces during this procedure.
1. Disconnect the negative battery cable.

If the vehicle's audio system is equipped with an anti-theft code, make sure you have the correct code to reactivate the audio system before disconnecting the battery!
2. Raise the vehicle and support it on safety stands.
3. Carefully disconnect the oxygen sensor wiring connector.

4. Carefully unscrew the sensor from the exhaust manifold (upstream sensor) or the catalytic converter assembly (downstream sensor).

5. Before installing the sensor, apply anti-seize compound to its threads (new sensors are usually already coated with this compound).
6. Install the sensor in its original position and tighten it securely.
7. Connect the wiring.
8. Lower the vehicle to the ground and road test it. Check the control module memory for diagnostic trouble codes.