Check Exhaust System
WARNING: This page is about a different car, the 1995 Ford RV Cutaway, 1995 Ford Econoline, 1995 Ford Cutaway, and 1995 Ford Club Wagon. However, it is still accessible from the selected car via links, so may be relevant.
Visually inspect exhaust system for dents or kinks which could cause restriction. If exhaust system is okay, go to next test. If dents or kinks are found, repair or replace faulty component(s) as necessary and go to next test.