P0102 on a Subaru: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

You can usually drive a Subaru with P0102, but the engine may run rough or stall until the sensor is fixed.

What P0102 means on a Subaru

On a Subaru, P0102 means the mass air flow sensor signal is lower than the engine computer expects. The MAF sensor measures incoming air so the computer can set the fuel mixture. A weak signal usually means the sensor is dirty or failing, or the intake has a leak.

Is P0102 common on Subarus?

P0102 is common on Subarus with higher mileage, especially Outbacks, Foresters, and Imprezas. Subaru MAF sensors get coated with dust and oil, sometimes from over-oiled aftermarket air filters. Cleaning the sensor is often enough to restore the signal.

Commonly reported on: Outback, Forester, Impreza, Legacy.

Symptoms

Check engine light on
Rough idle or hesitation
Stalling at stops
Worse fuel economy

Common causes

most common: Dirty or contaminated MAF sensor
common: Faulty MAF sensor
common: Over-oiled aftermarket air filter
less common: Wiring or connector problem

How to fix it

Fix	DIY?	Typical cost
Clean the MAF sensor with MAF cleaner	Yes	$10–15
Replace the air filter with a proper one	Yes	$20–50
Replace the MAF sensor	Yes	$80–250
Repair the wiring or connector	Mechanic	$80–200