EGR valves cause many concerns on Ford 6L diesel engines: the most common one being that the valves stick due to excessive soot deposits. While there are few simple services that can be done on these complex engines, cleaning your EGR valve just happens to be one of those rare simple ones.
The EGR valve service involves removing the valve and cleaning it with combustion chamber or carburetor cleaner. With the valve removed the intake ports where the valve is installed are also cleaned. Doing this service will prevent many an EGR related driveability concern due to a sticking or plugged valve.
Perform this service every time you replace fuel filters and it will only add to the reliability of your truck.