Possible Causes

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Ford RV Cutaway, 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, and 2003 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.

Snow, plastic bags or other foreign material may restrict airflow at air inlet.
Misrouted air cleaner ducting.
On engines recently repaired, rags or cap plugs may have been inadvertently left in an air inlet pipe.
Exhaust Back Pressure (EBP) device may be closing during cranking or stuck closed.
Tailpipe or muffler may have collapsed or been damaged.