98 cutlass stalling shutting down while driving

I have a 98 cutlass v6 that shuts off while driving. When it first started it seemed like it was happening while turning a corner or going down hill. It ran fine for two days then on the way home from work it did it again. I had a check engine light on for awhile before this started happening so I decided to get the codes read. They were o2 sensor and egr. I cleand the egr first. Drove the car for a day then it started stalling again. I changed the o2 sensor, drove fine for a day then it started shutting down again. I cleaned the maf sensor, ran fine for a day then started shutting off again, on all road surfaces. Note each time it shut off I was able to start it right back up again with no problems. The problem has become so frequent that I am afraid to drive it til i figure out the problem. Has anyone had any experience with this? Thanks in advance for the help.

Missing info, which engine,? Does it do it slowing down, under power, coasting?