KA-T hesitation problem, please help.

[KAs14slider]

Hi guys, I just got my 96 240sx turbo'ed and I am having some hesitation problems. The car runs fine up until it goes above 5psi. After I hit 5psi, the car will stutter and hesitate. I know I have an exhaust leak somewhere around my cat but would that cause the problem?
I have a manual boost controller that I need to install so I could limit it to 5psi but I thought you can't go below what your wastegate is set at, right? I think a stock t28 wg is at 7psi
I just ordered a wideband today and right now I am just using an SAFC II with a narrowband to try to tune the car so that it is driveable.

Anyone have any suggestions or tips on what may cause my hesitation?

Alex.

My setup:

-Bottom mount s14 t28 at stock boost (7 psi i think)
-Godspeed FMIC
-Megan 2.5" catback
-Walbro 255 pump
-stock FPR
-JGS tools 0.050" oil feed restrictor
-SAFC II
-SR 370cc's
-stock s14 MAF
-timing fully retarded at distributor
-NGK brk7's gapped to 0.28
-using 93 octane gas
-Blitz DD bov & boost guage t'eed into FPR vac line.

[KAs14slider]

Well, we finally figured out the problem today but then it came back. Turned out I had a bad engine ground, as soon as we fixed that the car ran perfect with no hesitation and with my ngk's gapped to .35. So I was driving on the highway and did WOT in 5th for about 6 sec to catch up to my buddy then I let off and when I got on it again (not WOT) the car started hesitating and sputtering worse then before. Since then I got new bkr7e plugs gapped to .32. Car still hesitates and I can't accelerate at all. I have no idea what the problem is now. I guess I can try regapping them to .35 I doubt that will help, the hesitation is a lot worse now. My coolant and oil is clean so it's probably not a headgasket, and I guess I could always try to check the compression again.

[tiresmokes13]

I'm sure you already checked for boost leaks correct?

Any smoke shooting out? Black, white?

[bo2o]

put your safc back to default. no changes.

see how your car runs after that.

put it back closes to stock. fuel pressure closer to stock. or lower.

.
alsho how do your car idle?

either you dont have enough fuel. maf. something.

but put everything closes to stock as you could.

sparkplugs are good you went with the next one up rite?

[sunnys14]

why is your timing FULLY retarded at the distributor? recheck your timing, and set it at 16 btdc.