Wastegate will not adjust past 4psi -Turbo boost conundrum

[Turbolena]

2006 V70 R
Seriously out of ideas except that the new turbo is bad.

I had a qualified mechanic work on this project….

Despite adjusting the wastegate actuator up and down - the turbo only makes about 4psi of boost when not plugged in to the TCV.
And with the TCV plugged in only about 10psi.

TCV-replaced
Turbo holds vacuum
MAF replaced
IAT replaced (although I just cleaned and put old one in)
No codes except for REM -1D01- my gas cap cover doesn’t lock. But maybe this controls other aspects?

Car pulls strong except doesn’t fully boost. No apparent leaks in anything

Starting to get mad.

Any insights would be greatly appreciated.

[matthew1]

TCVs on P80 cars - the rule of thumb was stick to OEM. I think this is the same rule for P2s but I can't remember. Stock boost on P2R is 12 IIRC, so yea, you're 1/6th short if your boost gauge still holds its calibration.

[scot850]

What brand of TCV did you use? I believe the standard is only good to 12-14psi reliability wise.

Neil.