My Pontiac Vibe recently stalled out after starting which has never happened before. Restarted and drove about 100 yards and it stalled out again. This time the "check engine" light stayed lit. Had no acceleration when depressing the accelerator gradually and due to the location I proceeded very slowly to a Pontiac dealer down the road. While running this slowly the transmission shifted with a "clunk" and the car never got much above 15-25 mph. Had plenty of gas and had travelled a lot that morning. The car had been sitting outside for about two hours before this problem.
Any thoughts as to why this happened? What should I expect in the way of repair?