RB20DET S13 Chewing through gas/feeling underpowered

[rbmiklary]

Hey guys,

Wondering if anybody can point me in the right direction or knows something I don't, will give the mod list first just to give everyone a frame of reference. Motor is for the most part stock except for the following.

RB20DET 92 S13
-Wiring Specialists Swap harness complete engine trans
-CXracing front mount intercooler kit (I know)
-walbro 255 (or so I'm told from previous owner, but I believe him)
-AEM Adjustable Fuel Pressure Regulator
- z32 maf (thinking what could be my problem)
- hks sport exhaust
- amperformance downpipe (awesome, probably only swap downpipe that clears the steering shaft)
- pop filter (random autozone one, mine was beat had no choice)
- NGK BCPR6ES's

Now with the exception of the fuel pump the rest was installed by yours truly, car seems good but feels like it has a slight missfire midway. Also feels like it should be faster, lacking pick up. I should mention when changing plugs recently noticed that cylinder one was far cleaner in comparison to the remaining five cylinders. All seemed covered black soot showing my rich condition but not so much in cyl 1. Black soot on the back bumper as well.

Now I have fuel pressure set to factory 43 lbs, stock turbo factory psi, stock injectors. Stock computer. Was thinking the rich condition could be caused by the Z32 maf for obvious reasons, and I have a apexi neo kicking around and a wideband o2 w/gauge that I could mount up but was curious if anyone ran into something similar, or had any thoughts as to what I could be missing.

Thanks,