After a long drive feels like the car is going to die on me. Idling goes up and down while on stop. This happened to me twice already, once when I am on a stop at a stop light. The car died, however, the all the lights were still on the dash board however the gear indicator on the dash board was gone. I couldn't press the gas. I had to completely turn off the car, change the gear to park and restart and it will restart and drive like nothing happened. 2nd time was when I was driving 45 minutes straight, the same thing happened, all lights were on but gear indicator on the dash board was gone and the car died. Brought it to the mechanic today, hooked it up on the computer and said that everything is okay and when he thought it was the alternator, it wasn't. What else could be the reason why this is happening?