well, welcome to Taurus hell.
membership is optional...
a few thoughts:
some years had issues with torque converter splines stripping out.
thought it was more gen4 but you never know
you need to check the TRS
switch. could be out of adjustment, or bad
i would look closely at the wiring on the trs
switch and the transmission itself.
maybe vermin got to it? on my 98 i had a O2
sensor code only to find the
wiring chewed up for some reason. (it wasn't me..)
could be a issues with clogged valve body or failing solenoid.
thats probably more than most DIY can deal with
One last thing: clean and reseat ALL under-hood ground wires to chassis.
especially the one from the firewall to the engine block.
then the ones on the drivers fender well, and ones by the starter.
Its a long shot, but you never know.
you could also read solenoid resistance readings from the trannie plug
if you have a ohm meter and can get to it.