Q: How do I know the O2 sensor is good or not?
A: The only way to know if the O2 sensor is functioning normally is to check its responsiveness to changes in the air/fuel mixture, by Voltage Measurement or Waveform Simulation.
Use a 10-megaohm digital voltmeter. Hook up the voltmeter's red probe to the sensor's signal wire and the black probe to engine ground. (Use back probe method, DO NOT pierce the wire.) For a good sensor, voltage should fluctuate constantly between 0.1 and 0.9 volts after starting the engine for 2 or 3 minutes.
Q: Why should we replace the bad oxygen sensor?
A: Replace the bad oxygen sensor in time can reduce harmful emissions, increase fuel economy, improve engine performance, and prevent premature failure of the catalytic converter.
Q: How to Identify oxygen sensor's location?
A: Upstream location is between the catalytic converter and the engine.
Downstream location is between the catalytic converter and the tailpipe.
Q: How to install oxygen sensor?
A: Step 1 - Pull the plug and take off the oxygen sensor.
Step 2 - Compare the sensor with the old to ensure they are same model.
Step 3 - Slight tighten the sensor against wires damage and sensor leakage.
Step 4- Turn on the ignition,and use the scanner to cleared the codes.