Mass Airflow Sensor (MAF) : Subaru Legacy 2.5 L 165hp Gas.
One of the most important engine management sensors is the mass airflow sensor.A bad mass airflow sensor can cause your Legacy's engine to fail.
The density of the air entering the intake manifolds is measured by a MAF sensor.This information is passed onto your Legacy.The amount of fuel that enters the combustion chamber is controlled by the ECU, along with other sensor data.
If you determine that you need a new sensor, they are not too expensive.They are easy to replace if they are by the air box.
You will definitely feel it when the mass airflow sensor goes bad.Here are the most common symptoms of a malfunctioning sensor.
The check engine light will be triggered if the MAF sensor goes bad.It helps you narrow down the problem.The two most common trouble codes are:
The most common ones are related to the mass air flow sensor.There is a great video on how to diagnose a bad MAF sensor using a multimeter.