My car started having engine power loss a week ago. I would pull over and the car would die. I started the car, put it in drive and it didn't move. I put it in first gear and the car moved, then I moved it to second gear and went home. The car would not work in third gear or (D) drive. I took it to the dealership, they couldn't find any problems. I took it to a muffler shop (thinking the cat was old) no problems there...third shop, replaced throttle body...didn't work. Still waiting to hear if the throttle body was bad. A new one coming from GM overnight.