I have had the same problem with my 99 cavalier. Does it stall when you low down and stop on the busy highway or when your driving the car just dies?
Have you checked the battery and see if maybe the connectors going to the battery are bad? (I'm a girl and i don't know much so you guys that read this don't make fun
)
Right now as it stands my car likes to just start bucking and then dies when i'm at a stop sign idling. I'm getting it looked into. Seems like cavaliers all have the same routine (but annoying) problems.