Common symptoms of a defective MAF sensor on a Subaru:
- Check engine light stays on
- Engine runs rough or shakes
- Engine misfire detected
- Poor fuel economy
- Cruise control light may come on
- Engine hesitates under load or at idle
- The engine struggles to start
- Rough idle
A faulty Subaru MAF sensor will trigger fault codes such as P0101, P0171, P0174, or P0102.
How to replace Subaru MAF Sensor
Replacing the MAF sensor on a Subaru is very easy and takes less than 30 minutes.
- Park the Subaru and turn off the ignition. Set the parking brakes.
- Pull the hood release to open the hood.
- Locate Subaru mass airflow sensor to the engine air filter housing.
- Unplug the electrical connector by pressing on the sensor and pulling it away.
- Remove two screws that hold the sensor in place.
- Install the new sensor and plug in the wire harness. Start the car to make sure there are no performance issues. The check engine light should reset in two to three days as long as no other fault codes are present. To read other codes or to reset the check engine light right away connect an OBD-II scanner to the diagnostic port under the dashboard.
A bad Subaru MAF sensor can trigger various check engine codes such as P0300 or code for the O2 sensor, air volume, or something else.
While it is possible to clean the MAF sensor, cleaning the MAF sensor does not always work. If you decide to clean the MAF sensor make sure to use MAF Sensor Cleaner.
Problems with the MAF sensor can be challenging to diagnose at times. Especially if they are caused by a corroded or damaged wire harness to the sensor itself.