2001 Chevy Malibu Car losses power while driving.

My 2001 Malibu randomly losses power when I am drivng. I will be going down the road and the engine will cut out and all of my gauges (Gas, tacometer, spedometer, temp.) Will drop and the theft system light will come on. Then all the gauges and other pre ignition light will come back and I can put the car in neutral and it start right up. Also, sometimes before I even start the car and I turn the key to the ACC. Setting, my gauges and display light will come up like normal and then suddenly turn off. I then have to wait for them to come back on before I can start my car. I took it to a repair shop and they said it didn't do anything for them so they couldn't fix it. Since the problem started back in February, the problem has become more frequent. Please help me!