2000 Monte Carlo Stalling

So my friend has a 2000 Monte and she said it keeps stalling. It will run for a few minutes and than stalls. She lets it sit and restarts it and it runs for an even shorter amount of time. Each new restart it gets progressively worse. She was told by the auto shop she brought it to a year ago that it needed new o2 sensors. But I have never heard of an O2 sensor causing a vehicle to die. I know they can cause real drivability issues. If you have any advice on this it would be great.:screwy:

So in case anyone was watching this thread. The problem was the MAF sensor. Unplugged the MAF and she ran perfect!!! Replaced it with a remanufactured and it is all cleared up.

Thanks for posting back, many thiings can cause your problem, and the procedure to eliminate the usual suspects was just what you did.