Unplugging the sensor will set the CEL and throw a code, but if it runs better with the sensor unplugged, you need a new one on there. The truck won't run perfect with the MAP unplugged since it's trying to determine boost level based on a pre-programmed table in the PCM.

How much better did it run with the MAP unplugged? Enough to make it almost normal, or still a ways off? Almost normal means get a new MAP sensor. Still a dog means keep looking. What about fuel pressure under load?