2000 Dodge Intrepid Cut off while driving

Lately my vehicle has been cutting off more frequently. Originally, I thought it was directly related to the fact that my check engine kept coming on. The first reading indicated there was something wrong with my upper 02 sensor but that was checked out and it turned out it was fine. Then the check engine light came on again and this time it was determine that there was something wrong with my EDR reader ( I think that is what it is called). That was replaced and I had a tune up. My vehicle drove fine after that and the following day. Until my vehicle stalled when I was changing lanes, it was cold, but my car has cut off time when it was had not been cold as well. The steering wheel locks up and the oil sensor light comes on. Each time it does that I have to turn the vehicle off and restarted it and press the gas to get it back up and running. Something I notice is that my RPM reader gets very jumpy prior to my vehicle turning off on me. Instead of gradually dropping to 1 rpm when I am slowing down below 10-15 mph it drops below and then back up to 1 rpm. I don’t want to trade in my vehicle if it is a rather simple repair. Please help!