Welcome. Usually when someone has ATX issues, the first thing we ask is whether the ATF has been changed in the past 30K miles or so. And we would also ask to check if the level is correct and whether the color is clear pink/red and to compare to a quart of new ATF Mercon.
This might help you decide what to do.
Originally posted by GeoPappas:
The following is from the Ford TSP (Technical Service Publication):
Diagnostic Trouble Code (DTC) P0731/P0781 indicates gear #1 incorrect ratio. DTC P0732/P0782 indicates gear #2 incorrect ratio. DTC P0733/P0783 indicates gear #3 incorrect ratio. DTC P0734/P0784 indicates gear #4 incorrect ratio.
DTC P0750/P0751, P1751 indicates SS1 electrical malfunction. DTC P0755/P0756/P1756 indicates SS2 electrical malfunction. DTC P0760/P0761/P1761 indicates SS3 electrical malfunction.
Possible causes:
-- Internal Transmission.
-- Damaged solenoid.
-- Solenoid circuit open or shorted to VPWR or GND.
-- VPWR circuit open or shorted.
-- PCM damaged.
* Key off.
* Disconnect transmission vehicle harness connector. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
* Connect DVOM between the VPWR pin and the suspect solenoid pin at the transmission vehicle harness connector.
* Perform KOEO Self-Test.
Edit. Should you decide to change the ATF,
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=tranny&Number=992476&page=0&view=collapsed&sb=5&o=7&fpart=1
In addition, if you did not mention the DTC O732, I would have suggested you check the connections for the VSS and TSS. 
