Some 2010 Ford E-Series vehicles equipped with the 4.6L, 5.4L or 6.8L gas engine and built on or before 6-22-10 may exhibit a lack of power on acceleration due to an engine air cleaner inlet restriction at the upper air deflector on the radiator core support.
1. Open the hood and remove the S-shaped air cleaner inlet tube from the upper air deflector using a twisting motion.
2. Inspect the air inlet opening in the upper air deflector for the flexible plastic/rubber flap that may be out of position and obstructing the air inlet opening. If the flap is obstructing the opening, reposition by directing it down in front of the A/C condenser. If the flap is correctly positioned, this bulletin does not apply. Refer to normal diagnostics in the Powertrain Controls/Emissions Diagnosis manual.
3. On vehicles with the 6.8L engine, if the air deflector was repositioned, remove the remaining throttle body inlet pipe.
4. Inspect the corrugated throttle body inlet pipe for damage. Be sure to extend the accordion pipe and inspect for tears/holes. Replace the throttle body inlet pipe if damaged.