Need Advice! No Power!

[scottie]

Ok here is the setup im running:

Z32 MAF
FPBig28
Greddy FMIC
AEM fpr w/guage
Nismo 740cc
NGK BKR7E plugs
Greddy Spec 2 Controller
Apexi PFC
Walbro 255 pump
Deatchwerks Hardwire kit

Ok. The problem started just a week ago. The car has been professionally tuned by Steve Kan of Gotham Racing. The car was running perfectly for 2 weeks at 16-17 psi. Nothing seems weird, everything was running tip top. So about 5 days ago, i get into the car and everything seems normal, idling fine, revs good with no load. However, once i get going, if the car goes into boost at all, no matter what gear, the car boggs and doesnt do anything, as in no power. If i let off the throttle, and goes back into vacuum, the car will run fine. So basically once the car gets into boost, it does nothing, just boggs and jerks. If i take it easy on the throttle, keeping it out of boost, i seems to drive normal. I pulled the plugs and according to them it seems to be getting too much fuel. Its not the ecu because its been tuned. Each plug looks the exact same, so whatever is happening, its doing it on all cylinders. Can someone point me in the write direction? Here is what i've done so far:

1) Put new plugs in
2) Checked intercooler couplers and all vacuum hoses
3) Checked all my wires to see if a sensor has come unplugged

I know its not wiring like some people suggested, otherwise the car would have never ran perfect before. One thing i did notice before the car started acting like this, is when we were tuning, the car would randomly show lean on the wideband, and only occurred occasionally. Could it possibly be my fpr? Any help from you guys would be greatly appreciated.

-scott