4Pcs Oxygen Sensor for 2017 2018 2019 Nissan TITAN Armada 5.6L Upstream Downstream 234-9148 234-8020 Front Rear Car Accessories

Must Know Before Buying:

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.

Please take a video clip of the voltmeter and contact us if our sensor:

Goes above range between 0.1 and 0.9 volt

Remains below 0.5 volts

Stays fixed at a particular voltage

You're free to choose replacement or refund if our sensor fails to work, in this case.