This is a weird issue I have. i used soap and water to find the leaks I had. My turbo likes to creep to 18psi-20psi, running 450cc, bucks at 5500 then sometimes 6000 at WOT, my wideband will go -- when it bucks. But even if I go 60-75% throttle to keep around to 10-12psi it will buck very little at 5500 rpm. It's always at that point. The head is completely rebuilt so is the engine.

Things I have done:
Boost leak test many time. none I can find.
Cleaned and gapped plugs to .28 ( their new nkg )
Checked for exhaust leaks. I do have a leak coming out of the flapper from the turbo. Probably explains the creep. (Seafoam)
Adjusted the greedy type s. Also replace the o-ring cause it was leaking. Yes this bov is a peice of sh!t.
Bov is recirculated

Things to do next:
Oil pan gasket leaking pressure???
Fuel pressure. I'll be surprised if it's out of adjustment. I always have it at 43 psi
Leak down test....

What am I missing?