my car did exactly what you described. except mine didn't buck to a stop probably because i have a manual (im assuming your auto tx)but i watched my rpm gauge buck pretty bad when coming to a stop. if your not auto still read below, might still be relavent.

turned out that mine was the IAC(intake air control). what it does is control the air when the the throttle plate is closed to achieve smooth idle.

Multi meter test
test pins 1 / 4 and 2 / 3
should read 38 to 52 (Haynes manual -at your own risk)

quick test
have a friend listen for a click at the sensor when the key gets turned (dont start it) no click = your done, start trouble shooting why it doesn't engage. if it does click you still need to try the meter test.



I figure since I cant stop fixing the damn thing, I'll just create more problems to work on. The stock pile has begun. Parts PArts PARts PARTs PARTS!!!
I'm a novice listen to what I say and make your own conclusion. If I'm wrong tell me and I will learn. Thanks be to the 2gnt Gods may they grant me turbo and fruits of the Earth. Amen.