2001 Ford Taurus flashed theft light while driving and stalls. It does that intermittently. Starts fine.

You will need the system scanned to see what fault is present, left unrepaired the problem will in the end cause a lock out.

Usually it's the key. Try your spare and see if the problem stops

sounds like the key sensor has failed its a ring shaped part that goes around where you put the key in under the cover

Moisture is getting into and shorting a component in the electrical system, killing the spark. Someone is going to have to identify where and fix it.

Yes, the chip in the key is not programmed to the computer for some reason. May have to take to dealer to fix this problem. The anti theft light coming on is a bad sign, where, for security reasons, if the key doesn't match up with what the antitheft computer expects, then the car's engine shouldn't work.

I have a similar problem, intermitently the car will not crank. The dome light stays on which eliminates the battery. The clock on the radio turns off when I try to start it. Th Theft light is solid red the first time I try to start it, then latter after a few tries the red light is off, but it still wont start. I tried moving the shifter when in park, I even tried starting it in neutral. After a while it starts and once started it runs fine. I will have to take it to Ford next week. We just do not want to drive it, it is too unreliable. It is a 2000 Ford Taurus.

you have to turn off your anti theft for it to start

Sell It

probably the vehcile speed sensor

Either you may be using a key that you had copied from the original or your chip went bad in your original key. Most of cars now a days have the key censor in the key so if it is the incorrect key it will not start your car or if it does not read that chip it will not start