My gauges do not work sometimes. What could it be?

[aguerrero]

I have a 2000 Chevy Malibu. When I start the car, the gauges do not work (temp. and gas), the power windows do not work, and the A/C does not work. Then 2 or 3 minutes go by and everything works. This happens off and on. Finally, my check engine light went on, it read that there was a malfunction in the crank shaft sensor and oxygen sensors. Shortly after, my car died while driving it. After many attempts to start it, it started but I was only able to drive it a few yards and it stopped again. I cannot drive it since it stops off and on. What kind of electrical problem do I have? Is the electrical problem causing my car to stop? Or is it the crank shaft sensor? A mecanic told me after reading the computer diagnostic that by changing the crank shaft sensor my car will not die again. Is this true? About a year ago I replaced the fuel pump, oxygen sensor, and fuel filter. I also replaced the fuel pump a few days ago just in case it was clogged. Help, PLEASE!!!