Diagnostic and Repair Information on Poor Engine Performance with DTC P0101 - Mass Airflow Sensor Performance Set

When diagnosing the cause of a poor engine performance condition along with a diagnostic trouble code (DTC) P0101, technicians should first remove the air cleaner assembly upper housing and inspect for a loose or mispositioned air deflector at the inlet to the housing. This deflector is snapped into the lower housing during assembly as shown below.

If the deflector is not seated properly, it may cause improper deflection of the air entering the air cleaner housing, resulting in a false reading of air flow by the mass airflow (MAF) sensor.

If you find that the deflector is not properly seated in the housing, reinstall the deflector and lock it in place with a self-tapping screw using the procedure below. It is not necessary to remove the air cleaner assembly from the vehicle to do this procedure.

1. Remove the six TORX® head screws from the upper air cleaner housing. Remove the housing and filter.
2. Make sure that the air deflector is fully seated as shown above.



3. Drive a self-tapping screw, P/N 11508601, into the air cleaner housing (upper position of air cleaner housing) and deflector in the area shown above, securing the air deflector to its fully seated position. Tighten the screw to fully seated. A magnetic tip on the driver is helpful.
4. Clean any residual plastic shavings from inside the air cleaner housing.
5. Install the air filter and the upper air cleaner housing.

For vehicles repaired under warranty, use: