car cuts off on 1994 Pontiac Bonneville

the car cuts off at low speeds less than 15000rpm's. But it restarts immediately! have replaced the idle sensor in it. Idles perfect in park, never cuts off. In drive if you take your foot off the gas the car cuts off.

Asked by for the 1994 Pontiac Bonneville
Try cleaning the throttle body, if it is carboned up it will cause this problem.