Engine Exhaust System problems of the 2004 Chrysler Concorde

On our second engine now. The second engine is now doing the same as the first before it quit. The check engine light is now on and no one can seem to tell me why the car keeps stalling while driving at a variety of different speeds and conditions. When it stalls the car is still partially on. The power steering goes out and I can not accelerate but there are still a couple of lights on the display the same ones that turn on when you turn the key half way forward. I think the electrical is still on but the engine is off. Does that make sense? I am not a mechanic, but they can't figure it out either so I guess that wouldn't help! the check engine light code refers to the catalytic converter, but I have been told that it is fine. This is a Concorde lxi actually should be called pos instead of lxi. We have replaced the cam sensors, the cam shaft, battery, alternator, battery cables, the transmission, and the engine. It still quits several times a month. This all began before the warranty went out, it paid to replace the first cam sensor. This was my first car and I didn't know what to do after the warranty wore out. I still don't know what to do. Mechanics tell me to get a new car I can't afford one.