high speed(rpm) engine cuts out??? help!!!

[krahs912]

Mods
Apex i AFC Neo Fuel Management
greddy fmic
hks exhaust
Greddy Profec B Spec II Boost Controller
hks ssqv
all mods were done last year on stock 40k supra and car ran great!

i have a 95 supra tt the engine cuts out in 3rd-4th gear,5000 rpm and up, 17psi of boost. have code 34. seems to be boost related as soon as i get 17psi there is a mometery cutout. not a miss or skip. engine stops and comes back. not sure if it fuel or spark. i cannot turn boost down. i disconnected Spec II and still get 17-18 peek psi of boost 3rd- 4th gear, seems high with no controller? car runs great in 1st-2nd gear only gets to 13-15 psi. wideband shows rich at all rpms,(not to rich) plugs look good gaped at .025 tested turbo actuator moves freely with 15psi of pressure. only has about a 1/2 in if travel but it does move freely. is that enought? if it was the fuel cut off in the ecm, wouldnt the engine shut down till the key was cycled and started? timing belt jumped 2 teeth 2 months ago put new belt,tentioner,and idler all toyota parts. dont think its related but thought i should mention it. this cut out problem did come at same time. im stumped please help want to go fast again!! THANKS