Keith, What are you showing for boost pressure at around 13 or 14 hundred rpm's you should be around 45+psi, my C13 will hit 49 psi full on at about 1300 rpm's.
Low power could be a few things or a combo, low fuel pressure, transfer pump, transfer pump sucking air in the fuel line, fuel pressure regulator, air leaks in your turbo to head piping, aftercooler leaking. I wouldn't think it would be a injector as you don't have that many miles on the motor.