Yea its on the AFPR, set to 37 psi

I never really tried pumping the brakes with it disconnected, because the pedal is solid and cant really do that.. i just drove it for a couple kms and was getting the same problem.

When I hold the throttle at say 25%, and let the RPMS and boost build slowly, it starts studdering and spiking lean.

If i knew how, id throw up the log