As has been said already, oil in the intake and boost controller hose can be coming from the crankcase vent hose which vents into the intake pre-turbo. The quick way to see if this is where the oil is coming from is to run the crankcase vent to atmosphere with a longer length of hose, and block of where it went into the intake. Clean out the intake after the turbo, and drive the truck for a week or two and see if the oil comes back. If not you've found the issue, and you can install a catch-can on the crankcase vent hose. If there's oil in the intake post-turbo now, then its time to investigate the more expensive possibilities.