08R320CDI

So I'm getting a P0299 code, underboost, my question being, is it more likely that the vanes are stuck, or the actuator isn't working right? Can I check the vanes by pushing or pulling on the actuator arm? Then my next question, is there a turbo that doesn't have the vvt crap that I could replace my current one with, and would it cause issues not being vvt? Simple is better, and I'd rather have something with the same lag, or a smidge more lag, that won't have issues later on. I'm also looking into swapping for one of the newer version om642 turbos as a back up. Any ideas for me?