I've also been gettin that code but I put it down to me puttin a slightly bigger turbo on and not yet having the map adjusted! But I'm not 100% sure
Update and let us know if you sort it please 
Your problem will absolutely be down to having a bigger turbo than it's mapped for.
It's basically the new turbo is producing different figures on the maf that isn't correlating to the expected boost pressure/throttle position. Its a conflict in the 2 load readings and closes the throttle as it thinks there is an issue with the dbw pedal system.