Hello everyone, I'm new to the forum.......have a 2004 Mach 1 automatic that previous owner took good care of but car sat for about 2 years. I've changed oil, new plugs, new coils, fresh fuel, new battery, new JLT Ram Air Intake and added a MAC Prochamber and Cat-back system. Upon starting the car, it smoked something terrible and still does but after a few very short drive cycles, CEL came on and O/D light flashed and odometer had dashes. Read code and it was P0720 - Output Speed Sensor. Replaced sensor, cleared code and took on a short drive, same problem with O/D light and odometer and it doesn't want to accelerate in drive. Drop it down in second and it pull hard and runs good. Anyone have any idea what the problem could be? Thanks so much in advance.

 

might try the mach 1 registry, a lot of good mach specific tech. Not a lot of traffic in here these days. Your issue doesnt sound like a common one i've heard before.