Help diagnosing my Car

[nsn240]

This is a last resort... i've run out of ideas here.

Got the motor setup and put it ~9months ago... sat for a while cause i had my permit, i've put around 3000miles on it so far.
Setup is a sr20de motor, t25, MR tubular manifold, 370s, tuned ecu + safc, 3" dp test pipe and exhaust.
Im looking to solve the problem, not hate on the sr20de. (which sucks.)

Problem: it has slowly died since i started driving it consistantly. After it got done, and when i drove it occasionelly when it was sitting.. it pulled real hard, at 7psi just like a regular det would, spun first no problem, drove easy, no bucking and bullshit, good mpg.
Now, it idles crappy until warm, definately doesnt have the power it used to have. Has something wierd between ~2000-3000rpm when it feels like the clutch is slipping, or something is holding it back. gas mpg is absolutely horrible. It pops, backfires, and bucks during shifts and sometimes at partial throttle.
I've run a wideband on it, and partial throttle in 3rd, 4th and 5th gears is too rich, around a 11.8, but wot is ~12.0

It just doesnt pull like it used to, i've checked ignition, fuel, wideband, turbo etc etc etc

Looking for any idea that might help, thanks.

[punxva]

check your mafs

[slider2828]

Check your ignitor

[MOUNTAINGARAGE]

check your mafs

it could be as simple as a piece of crap lodged in the sensor. Just fixed one on a Toyota last week. Dealer wanted 1200.00 to fix, I charged her 75.00

swap your mafs with a known good one. to double check.

[nsn240]

it was the timing... somehow, it was wayyy to far retarded. so, we reset the timing... and the car runs tits again
I might possibly need another MAF when the tps was pulled (the ecu runs of the maf then) it had a crazy miss, and made it mad hard to time.

After all this... i get home, and post on sr20forum.. Apparently its the second mark from the RIGHT, not the second mark from the left. I definately chould have checked on that again... I guess i should get on fixing that.... so im still running at 15* retarded god DAMNIT

but even still its back pulling pretty hard like it should. I dont think the knock sensor had anything to do with it like i had though. Definately fun to drive again though
I went ahead and ordered a new coolant temop sensor, new vac lines, and i'd like to get my ecu done right with JWT, enthalpy or possibly a Calumsult, or similiar program.