Definately the TSS, or Turbine Speed Sensor... its an easy fix, order the part from ford... its something like $25. Then take off the driver side front wheel and you will see the sensor poking out of the side of the trannie with a wire attached... with some plyers pry the Sensor out of the socket. Disconnect the sensor from the wire... Then throw the old sensor over you sholder... Take the new sensor, ease it into the hole and gently tap it in till its all the way down. Reattach the wire, reattach the wheel and go for a drive in your smooth shifting ATX contour.
