04 chevy duramax lly, With codes cleared when starting throws code P0234. When driving, goes into limp mode, when it shift into 5th gear. Throws code P0700 and P2227. P0234 says overboost. The boost pressure is 27.5 psi (according to the snap on scanner) at idle. Hits between 36 and 39 psi then goes into limp mode. Replaced vane position sensor, still does the same thing. Looking for info what to check next.