I noticed whenever I downshift or let off the gas, it does not slow down the car. The rpm doesn't slow down as if I kept my foot on the pedal when in actuality its off the pedal. If I downshift without rev-matching the car does slow down for a little then the rpm stops dropping and stays constant again. When I had my Mach 1, I would use engine braking and I want to find a way to get it back. I don't know if this has to do with anything, but when I put my car into neutral or push the clutch in the RPM hangs above 1300 rpm until I come to a full stop. Also, between shifts when I push the clutch in the RPM goes up slightly (~100 rpm). I had a problem with my IAC before giving me rough idle but I got a new one and it went away so I don't know if that's the problem. Its not from Motorcraft though.