2011 Chevy cruze boost issue

I have a 2011 chevy cruze ive been working through issues as the previous owner did not take care of it. Ive replaced several parts on the car (to include turbo, all lines coming in and going out, maf sensor, turbo boost sensor, computer update due to speedometer spiking, barometric pressure sensor, map sensor, xtremes manifold fix, and probably more i cant think of) check engine light is still on (permanent underboost according to oriellys scanner was a current until i replaced the turbo), the ONLY way ive got it to boost and wont do it again is to pull the vaccum line off of the wastegate actuator. Any solutions???