How To Replace A Subaru WRX Oxygen Sensor
Looking down to see a check engine light on your dash can be very unnerving. If your Subaru WRX’s check engine light was triggered due to a faulty oxygen sensor, you've come to the right place. Replacing a part like an oxygen sensor can sound like a daunting task. Fortunately, it's a relatively simple job that can be done yourself with the right tools.
Understanding Oxygen Sensors
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An oxygen sensor monitors the level of oxygen in the exhaust gasses and reports that data to the engine control unit. Using that data, the air and fuel ratio is constantly adjusted to achieve maximum efficiency. An oxygen sensor is a small device about 1.5 inches square, with a wiring harness attached. You can read more about oxygen sensors in this post.
Where Is Your Oxygen Sensor Located?
There are multiple oxygen sensors on the Subaru WRX. The exact number and location varies depending on your model. Some oxygen sensors are located on the exhaust manifold. Some oxygen sensors are located lower in the exhaust system near the catalytic converter. Oxygen sensors are threaded, and install by screwing into a threaded hole in the exhaust system.
Replacing An Oxygen Sensor In A Subaru WRX
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You don't need to take a trip to the dealership service center or mechanic to replace your oxygen sensors. The only tool you need for this is a 22mm wrench. You will also need a new oxygen sensor. Here is a link to a front sensor and rear sensor that fit many different Subaru's made between 2014-2020. Replacing an oxygen sensor is a pretty simple process. The steps below are a general outline of the process that will work for many different Subaru's:
- Locate the oxygen sensor that needs to be replaced on your WRX.
- Spray the sensor threads with penetrating oil.
- Unplug the connector.
- Remove the oxygen sensor using a 22mm wrench.
- Apply anti-seize lubricant to the new sensor threads.
- Screw in the new oxygen sensor and tighten it with the wrench.
- Re-connect the new sensor.
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