Hoping someone can help with some ideas. My friends 2005 S60R burnt a valve and I took the head off and had the valve replaced and the head surfaced. I reassembled and after a little confusion with setting the VVT preload I have the car running and no codes are present. The car seems to run well but the mid-range power is just not there. seems like the turbo is not working as it takes a lot longer to build RPM. At this point it starts right up, revs nice, engine sounds good and no codes but def feels like 200HP NOT 300HP.