My car has had the problem of shutting off while driving, wondering if someone had some advice?

I recently bought a 1997 Oldsmobile Regency with 135,000 miles on it. For the first week everything was in working order, no problems with the car. Then i was driving down the road one day and all of the sudden the car completely shuts off, with no stalling or sputtering. I have since replaced the fuel pump, oil pressure sensor, and throttle position sensor. I have also checked all of the fuses and relays, with no luck at all in fixing the problem. It has continued to shut off while i am driving at least once or twice a day. I cant think of anything else it could be. Could someone please give me something to lead on?