An illuminated Check Engine Light could indicate that one or more of the ignition coils has failed due to excessive spark plug gap. To fix this problem, the ignition coils that have failed, the spark plugs, and all coil boots should be replaced.
Ford F-150 Problem Reports
RepairPal Verified Ford F-150 Problem Reports
Tubes for the EGR system (exhaust gas recirculation) can break, causing an exhaust leak and noise under the hood.
If a noise from the rear end is heard when going around turns or after driving at highway speed for an extended period, there is an updated differential clutch kit available.
The EGR orifices in the intake manifold may plug with sludge. If the truck has high mileage, this may cause engine misfire when first accelerating because too much EGR gas is directed into the cylinders of the unplugged orifices. This makes the mixture lean, which causes a gradual stumble that increases in severity until repaired.