TSS is the Turbine Speed Sensor. I had that problem with my '95 Mystique. A rather inexpensive part and theoretically easy to change. Changing it could take anywheres from 15 minutes to 3 hours; I'd be looking at the 3 hours as we live in the upper Rust Belt. There is a "Howto" in the ATX/MTX forums. Not sure how close you are to the twin cities but you could get a discount on parts from Steve at Tousley Ford.

Later. Pepse.

'95 Mystique LS Young America, Moonlight Blue, V-6 ATX, LOADED. REMEMBER: Always fasten your seatbelt as it makes it harder for the aliens to suck you out of your car.