Same thing happened to me after driving a new 2000 svt. This particular car seemed to be running rich (small black cloud coming from rear exhaust upon startup and VERY sooty exhaust tips for 150 miles). I don't know whether or not this was the prob, but when I got my (slightly) used 98 svt, this bucking problem was not in evidence at all. I concluded that it was a problem specific to the car, and not just my driving habits.
Hope I helped, Sam
