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This guide provides instructions on how to replace the oxygen sensor on a Honda Civic. 

Table of Contents

Even though oxygen sensors are not particularly maintenance items, they often start to fail around the 100,000 to 150,000-mile mark on modern Honda vehicles. Once the oxygen sensor on your Honda fails, you will notice the check engine light stays on and a decrease in fuel economy. 


  1. Park the Honda on level ground and allow the engine to cool down.park honda and get ready to change oxygen sensor
  2. When replacing the upstream oxygen sensor (Bank 1 Sensor 1 or Bank 2 Sensor 1), open the hood. If you are replacing the downstream oxygen sensor (Bank 1 Sensor 2 or Bank 2 Sensor 2), you should jack up the vehicle as these sensors are accessed from the bottom of the engine.
  3. Locate the oxygen sensor on your Honda oxygen sensor locationThe upstream oxygen sensor (Bank 1 Sensor 1) is mounted on the exhaust right before the catalytic converter. Bank 1 Sensor 2 is mounted after the catalytic converter and can be accessed from under the car.
  4. Disconnect oxygen sensor wire harness. Use an oxygen sensor socket to remove the oxygen sensor from the catalytic converter. Turn the oxygen sensor socket counterclockwise to remove the O2 sensor.HOW TO LOOSEN HONDA OXYGEN O2 SENSORIf the sensor doesn't come loose, spray penetrating oil near the threads and let it soak for at least fifteen minutes.
  5. Remove the oxygen sensor. removed honda oxygen sensor
  6. Install a new oxygen sensor. Apply a small amount of anti-seize to the threads and hand-tighten the sensor in the exhaust. Using a torque wrench, tighten the new oxygen sensor to 33 ft-lb. If you don't have a torque wrench use the ratchet to tighten the O2 sensor until it is on snug tight.torque new honda oxygen sensor to 33 ft lb
  7. Connect the electrical connect by pressing the two ends until they click.connect honda oxygen sensor

We replace the upstream (sensor 1) oxygen sensor, which is accessed from the top of the engine. The same procedure is used to replace the downstream oxygen sensor, but that sensor is easier to access from the bottom of the engine.


When your Honda oxygen sensor fails, you will decrease in performance such as:

  • A decrease in fuel mileage
  • Difficulty starting
  • Check engine light on
  • Loss of power
  • Excessive smoke from the tailpipe
  • Failed emission (smog) test
  • Hesitation, poor acceleration
  • Rough idle
  • Possible codes P0420, P0135, P0141, P0155, etc.

Use an OBD-II scanner to read the codes via the OBD-II port under the dashboard to confirm the oxygen sensor is defective.

Frequently Asked Questions

How often should I change my oxygen sensor?

The oxygen sensor is replaced when they fail. In many cars, oxygen sensors fail around the 100,000 to 150,000-mile mark.

Can a bad O2 sensor cause a P0420 code?

Yes. P0420 code means that the catalytic converter is operating below the threshold. This code comes up when the catalytic converter is bad, or the oxygen sensor is defective.

Can I use a universal oxygen sensor?

Yes, you can. You may have to splice wires and will need to connect all four wires correctly. The new connections tend to corrode and cause problems down the line. Make sure to insulate the wires properly.

What is the Honda O2 sensor thread size?

The most common Honda oxygen sensor thread is 18 mm x 1.5 mm.

What are some symptoms that my Honda oxygen sensor is bad?

Check engine light and poor fuel economy are the most common.

What socket size is used on the Honda oxygen sensor?

7/8" or 22 mm socket.

Honda oxygen sensor torque spec?

33 ft-lb

Is it legal to use an oxygen sensor spacer?

No. In most countries, it is not legal to install an oxygen sensor spacer.

Honda oxygen sensor wire colors?

The typical color on the OEM Honda O2 sensor. The ground will be green or gray. The signal is white or black.


Honda Civic O2 Sensor Replacement Guide This guide provides instructions on how to replace the oxygen sensor on a Honda Civic.