How do I know the O2 sensor is good or not?
Check engine light on
A reduction in fuel economy.
Your catalytic converter fails unexpectedly
Exhaust emissions reach undesirable levels.
How to install the oxygen sensor?
Step 1 - Some sensors are equipped with a heat shield that must be removed before the sensor removal, this is performed by removing any mounting bolts.
Step 2 - By using a regular socket it minimizes potential damage to the sensor body and the threads, this technique helps avoid stripping the old sensor upon removal.
Step 3 - Then, locate and disconnect the wiring connector, this step should be done before removing the sensor if the wiring is still attached.
Step 4 - Its important that the wiring harness connectors are exactly the same, each sensor is unique to it's position and is located in the system by its connector configuration. (Note: some replacement sensors have a universal electrical connector that must be configured to the wiring of the old sensor.)
Step 5 - Use a small wire brush to help clean the threaded port to ensure a proper seal of the new sensor. Gently install the new oxygen sensor by hand while keeping the wiring and connector free from bends.
Step 6 - Gently tighten the sensor while keeping wiring free from damage, these sensors need to be fairly snug to avoid leakage.
Step 7 - Once the sensor is tightened, reinstall any heat shields or bracing that had to be removed.
Step 8 - After the heat shield has been reinstalled, mount the connector to it's holder and reattach the connector back onto the wiring harness. If the car has diagnostic trouble codes, they will need to be cleared.