Random stalling issue

I will start off with this information first because I am not sure if Ii is relevant or not. (I had a bad tire on the front passenger side that caused a tremendous amount of wobbling vibration I drove it that way for a few days before I realized that it was the tire). Last week while driving on the highway at about sixty mph I felt a slight stumbling. So, I got off the highway, the car seemed fine until I slowed down. It started to sputter. When the car came to a stop It sputtered, when I pressed down on the gas, the car sputtered, hesitated and shut off. I coasted It off to the side, let it sit for about thirty seconds then started it back up. It ran fine for about two miles then started sputtering and shut off. I started up again it ran for few seconds and shut off. I could not keep it running. I had it towed home. I put two bottles of heat in thinking maybe there was water in the gas. I waited about two hours then I tried to start it again it idled smooth until I put it in gear, it sputtered vibrated hard then shut off (I repeated that several times). I let it sit over night, started it up in the morning, it idled smooth for about fifteen minutes. I took It for test drive, drove it for about three miles down a hilly back road. The car drove like there was not a thing wrong with it. So, I changed the tire out and the car drove fine (for about a week and a half). Yesterday, I got a flat in the tire that I previously changed out and had to put the bad tire back on until I could get to the tire shop that was about ten miles away. Before I got there my car started to sputter, I got to a light and the car did the same thing as It had done the week before. I had to have the car towed to a shop because I could not keep it running. The mechanics tell me that they cannot figure out the problem. There are no codes and the engine light is not on. They tested the fuel pressure and a few other things and everything seems good. Not to mention, they say that they let the car run for a couple of hours and it ran fine. I am confused! Someone please help me understand this.