I am still fighting this issue... lack of power, and no CEL, or even pending codes. and it is hit and miss too boot. sometimes it is fine, other times its not.
Here is what I have done.
1. pressure checked for air leaks...
2. tune up using OEM spark plugs about 15K miles ago
3. New turbo about 5K miles ago
4. New intake 9 Months ago
5. Checked the entire PCV system... all good
I think I am going to do a compression test this weekend...
Ready too just trade it off...