RE: 2000 FFV taurus engine miss
I also have a FFV 2000 Taurus that has exhibited the same kind of problems. Mine would have an intermitant miss at idle that went away at highway cruising speeds. Engine idle would drop down below 500 rpm when coming to a stop, much like a torque converter not disengaging. I took the car to Autozone to get any DTC's that may be stored; it had none. Here what I've done over the course of the past year.
I bought an OTC professional fuel injector cleaner canister and used several cans of their Pro-Injector cleaner and several cans of Decarbonizer.
I have installed Autolite APP103 double paltinum spark plugs and NAPA Belden ignition wires.
I checked fuel pump pressure and it is good.
I bought a new EGR and pressure feedback sensor and new throttle position sensor.
Installed a new PCV and air cleaner filter.
I cleaned the MAF with CRC electrical cleaner.
I hunted for vacuum leaks and checked for leaking vacuum hoses and a bad brake booster and found no leaks or defects.
I installed a new temperature sensor; the one that works for the PCM, not the dash guage.
I bought a new ignition coil.
I checked the brake light switch and it is good.
I checked the EGR passageway for carbon build up and found it to be clear.
I have installed a new IAC that WAS bad.
I checked the 4 oxygen sensors with a VOM and they are good.
The MIL works at system start-up but has never come on during driving.
I took it to the local Ford dealer and they couldn't find anything wrong.
Finally I did this last night.
I bought 3 new plugs and installed them in the front bank of the engine since it was easy to get to. (I didn't feel like removing the plenum just yet to get to the rear 3.) I removed the air cleaner box and removed the connectors, one by one, that go to the temp senders, the transmission shift selector, vehicle speed sensor, camshaft position sensor, the EGR vacuum control valve, just about anything that had a connector I removed. I sprayed the CRC electrical contact cleaner in the sockets and in the sensor plug of each sensor and blew them dry with compressed air. I also tightened the spark plug wire terminals at the plug end for the 3 I bought last night. Since I did this spraying of connectors and tightening of plug terminals the engine miss and transmission problem has gone away. I'm crossing my fingers before I say it's fixed; but for now it's 100% better. I am reminded of an 89 Aerostar I had that had problems at the electrical terminals to sensors and cruise control. I have read and heard from others over the years about how notorious Fords are for electrical connectors that are poor and work intermittantly as the vehicles get older.
BTW, the car has 99,700 miles on it and these problems have with the car since about 80,000. I hope this helps.