Call that dealer and ask to speak to service manager, call again and talk to the parts and service director. Call again and ask to speak to the dealer principle. Call the nearest dealer to that dealer and talk to the SM. Call Ford customer service. Do all of this within a few hours and you will have sucessfully completed a major C. F.. I would deny the intake to Ford customer service but admit you have an aftermarket muffler. Ask customer service why you were charged $250 to diag your truck when you are still under factory warranty. They will come down on that service advisor hard, especially if the service manager dosen't like the guy.