Vehicle speed sensor

i've got an 01 magnum in my 72 dart with a lock up 904. every once in a while, when you come to a stop, the rpms will drop enough to stall the engine. seems like it's when the tranny down shifts from 1st to idle is when it will do it. i've read that the computer needs to see the signal from the vss to adjust the rpms to prevent this. it's just every once in a while, so i just hold a tad bit of throttle till the car stops. what ralphie did is probably the solution to this. wish i had'nt cut the wires off now. lol. dave.