First things first, what are your egts doing? If it was a boost leak, then you'd have noticably higher egts and a bunch more smoke.
If the egts are normal or lower than normal, then you have a fueling issue. For example, if your MAP sensor isn't "seeing" the boost in the manifold, then it won't tell the pump to add more fuel. If you don't get the fuel, you don't get the boost. And you can have a bad sensor and not get the code.
If your egts are higher and you have more smoke, then start chasing down a possible boost leak/stuck wastegate/etc.
Did you do anything recently to the truck that could have started this? Do you run an exhaust brake (that will contaminate the MAP and IAT sensors)?