Check The Mass Air Flow Sensor Unit

1. Remove the mass air flow and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>REMOVAL .
   NOTE: Do not disconnect the connector.
2. Turn the ignition switch to ON. (Engine OFF)
3. Using the Subaru Select Monitor, read the intake air amount. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DATA MONITOR .
4. Check that the intake air amount changes when air is blown to the mass air flow sensor unit in the arrow direction.
   CAUTION: Be careful that no dust enter inside the unit when air is blown.

   Courtesy of SUBARU OF AMERICA, INC.

5. After inspection, install the related parts in the reverse order of removal.

2. CHECK THE INTAKE AIR TEMPERATURE SENSOR UNIT 

Measure the resistance between intake air temperature sensor terminals.

Courtesy of SUBARU OF AMERICA, INC.