I take it that you're using G series ROMs being in Europe. What software are you using to tune? I know that some of the Rotrex kits need to be SD mapped, or at least are hard to map using MAF alone from what others have said.
There are 3 manifold pressure sensor scaling tables, have you changed them all?
BTW, if you're using Romraider I have some decent A01G/A02G ROM definitions which are compatible for Euro cars (I'm in the UK). Use the A01G definition if using OFT files, if using completely stock original ROMs then use the correct one. Both can be
found here. Stock ROMs can be
found here
How much DI are you running and what does your ratio table look like? How do you know it's at 100%?