That is wild and crazy.
My reply is a bit off topic, but then again, maybe not so much.
If you have a sudden loss of power in your E350 or E450 motor home after recent service, there is something you can easily check for.
Around year 2010, Ford had a recall on improper installation of the upper radiator plastic shroud. It is the plastic thing your oval air filter tube snaps into. An assembly line worker was installing the shroud incorrectly, placing a plastic flap in the wrong position causing air-intake blockage. If your local mechanic takes the shroud off, he too could easily and unknowingly make the same mistake.
It is extremely easy to check, taking just as long to open and prop up the hood. You simply unsnap the oval air filter inlet tube from the top of the radiator area and swivel it upward. Look where it snapped into. You should NOT see a black plastic blockage in the hole. If there is a blockage, you have to detach and lift up the top radiator shroud, flip the black flap away from the opening and lower the shroud back into position and reattach.
It is a power-robbing problem easily introduced. Your mechanic could overlook this if not familiar with it. It's very easy to get it wrong, and fairly easy to make it right again.
