i have an 02 mustang gt, the car was running great had tons of torque and power and now there is nothing. seems to have some low end torque then around 3,000 rpms it looses everything car can only rev to around 4,000 does not want to get up and go. had a misfire in cylinders 1 and 4 changed the plugs and wires but dont know whats wrong now still doesnt move??? any ideas??