Bad computer

So this is a 6.4 powerstroke. It has low mileage and has many problems. The truck loses throttle control and you have to turn off and turn back on. The truck will smoke a lot and then will not smoke at times. Sometimes exhaust comes through engine bay into cab most of the time, other times it will not. It will run really bad, sounds like a 6.0 and lopes and shakes truck, and then it will run great. When you turn the truck on, some things on interior will not get power. This sounds like bad computers to me. What could it be? I do not have the truck readily available or tools to experiment.