Possible Causes

WARNING: This page is about a different car, the 2008 Ford Pickup, 2008 Ford F550 Super Duty, 2008 Ford F450 Super Duty, and 2008 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Reset the air filter restriction gauge after repairing a restriction concern.

Snow or foreign material restricting the airflow at the air inlet
Misrouted air cleaner ducting
On engines recently repaired, rags or cap plugs may have been inadvertently left in an air inlet pipe
Tailpipe or muffler may have collapsed or been damaged