How to Clean an Oxygen Sensor

A pair of oxygen sensors.
  • 2-3 hours
  • Advanced
  • 0-200
What You'll Need
Face mask
Car jack
Axle/Jack stands
Soft-bristled brush
Paper towels

The oxygen sensors are very important components in a car's exhaust system. As a result of regular usage, products like oil and coolants settle inside the oxygen sensors over time. It is necessary to clean the sensor to ensure that performance is not negatively affected. If you do not clean the sensor, it could lead to problems like inefficient combustion and reduced performance, and it may eventually have to be replaced.

Note: Gasoline is a very flammable substance, so make sure to keep it away from any potential heat sources when performing this task.

Step 1 – Prep Yourself and Your Car

Before you start cleaning the oxygen sensors, be sure to pay special attention to safety. Protect yourself with work gloves, work goggles, and a face mask, especially when working with the gasoline.

The first step to cleaning the oxygen sensors is to locate and remove them, but for this, you will have to use a jack to give you access. Park your car in a well-lit, well-ventilated, and clutter-free area. Then, use your jack to lift the car, making sure it is held in position. Use the axle/jack stands as well to ensure the car is lifted safely for you to work under it.

Step 2 – Locate and Remove

Slide under the car and locate the oxygen sensors that need to be cleaned. The oxygen sensors that go upstream are located in front of the converter, and the ones that go downstream are located right after the converter. Unplug the sensors and use a wrench to free them from their fittings.

Step 3 – Place Sensors in Container and Submerge

Get hold of a container with a lid that fits tightly along the edges to prevent any leaks. Also, make sure that this container is safe to put gasoline into before you continue any further.

Get in a well ventilated place with no flames or ignition sources, preferably outdoors.

Place the oxygen sensors in the container and then steadily pour gasoline from a gas can into the container as well. The quantity of the gas should be enough to fully cover the sensors in fluid. When you finish filling it, close the lid of the container, pick it up, and swirl it around, taking care not to shake or stir it too hard. This will help the gas to move and enter all parts of the oxygen sensors.

After you're confident the gas has been moved sufficiently, you need to let the container rest. Leave it in a cool, dry place overnight to give the gas enough time to react with the settlements and dirt on the sensors.

Step 4 – Re-agitate the Mixture

After having left the container overnight, you should now start with the remainder of the cleaning process. Lift the container and swirl it around again to re-agitate the mixture inside.

Step 5 - Scrub Sensors Lightly

If some of the dirt and sediment hasn't come off your sensors after their gas soak, you can now take a medium, soft-bristled brush to them. Dip the brush into the gasoline and lightly scrub each sensor, taking care not to scrub too hard to avoid causing damage. This should remove the rest of what might be left.

Step 6 – Dry and Fit the Sensors Back Into Place

Use a paper towel to dry the oxygen sensors and proceed to fit them back into their proper position. Use your wrench to tighten the bolts on the sensors so they are secure.