Car Keeps Dying on 1995 Oldsmobile 98

My Oldsmobile keeps dying. It will crank, sometimes, but after a few minutes it will die. After the check engine light kept coming on we took it to a parts store to have a diagnosic ran. It showed nothing was wrong.Does anyone have any idea on what can be causing it to shut off like it is. My dad replaced the fuel pump and we bought a brand new battery for it. One time it completely shut down. I mean everything just died. My husband could barly press the brakes down. Any ideas on what could be the problem?

Asked by for the 1995 Oldsmobile 98
If you have a Check Engine Light Coming on while driving, you have a code. A parts store is NOT a good measure of what is going on with your Olds. Have a real shop look at it. In California where I live and work. they OUTLAWED the parts stores from doing so-called Diagnosis because so many people were either being mislead or were getting ripped by buying parts that did NOTHING to fix their car, even though a parts salesman said it would do so.
3 answers
I'd look for a loose battery cable or ground first
It could be the catalytic converter or your distributor cap or just the timeing could be off