was driving down interstate doing 55, then all of a sudden my trooper slows down

Hello, Have you followed the factory maintenance schedule? When was the fuel filter last replaced. Do you feel exhaust coming from the tailpipe like normal? You should not be able to cover the tailpipe without the cover blowing off. If the pressure is low at the tail pipe, you may have a clogged exhaust. Do you hear any rattling over bumps?