my car will mot hold boost!there seems to be a fuel cut around 4200 rpm at wot this is where my boost usually would be at.i've checked the wastegate,bov,intecooler piping etc..to no avail.i juat had my fuel filter changed thinking that might be the problem but it's not.i just bought the walbro hi flo fuel pump,maybe that will help.i am ordering a power fc next week sometime do you think that will help?i have tried everything,any help is
welcome!
my mods-non seq turbos,street ported engine,intake

 

Is that your complete list of mods?
When you converted to non sequential, what exactly did you do? My guess is you somehow crimped a vacuum hose or capped the wrong ones causing your boost to skyrocket up passed the stock boost limit causing your ECU to cut fuel as a safety measure (pretty rediculous safety measure seeing as it could blow the engine as well) I would check over the vacuum hoses and make sure that you have not mixed any up. Give us some more info on fuel cut at near WOT as you hit boost as well as what your boost gauge reads when it is hitting this cut. I mean no offense by this, but it seems as if you have thrown mods on the car and not taken into consideration how much fuel is required to compensate, I wouldn't get on the boost until you have a properly set up PFC and fuel pump installed in addition to the possible vacuum hose problem. Just my thoughts.

Richard