2006 S60 2.0T B5204T5 boost pressure problem

[The_taker]

Hi, it's my first post here. I hope I'll get some help from you.

I went to dyno today for remap, and it turned out that boost pressure varies during RPM.
It builds up to 0,8 at 3000rpm and then drops to near 0, then builds up again and drops to 0 after 5000rpm.

So... service couldn't do a remap for me of course.

Did somebody have something like this? Could it be air leak or faulty TCV?

Please see dyno charts below: