turtle64b

I need help.... 2012 Stillen SC 370Z w/ A2A.

AFRs are consistently at least +2.0 above normal (cruising around 16-17, sometimes higher)
Startup is extremely bad, to the point of the car stalling out completely (AFRs reading 19-20)
Upon acceleration, AFRs will jump to about 15.5-16 and then fall back down to 14.7 while the engine is under some load, but then steady back out well above normal.
Sometimes at stoplights, the AFRs will bottom out (10.0) and the car will seem to bog down unless I rev it to about 1000 RPM and then it holds steady around 13 (1.5 below normal)
One MAF reads anywhere from 1 volt off of the other to right on the money from idle to under medium load, respectively.

Recent changes:
9# pulley installed 3/12, car ran better than with the 8# pulley without a tune revision. (EDIT: Car was daily driven for 5 days following pulley swap with no issues)
Power steering and tranny cooler installed 3/16-3/17, drove to Baker Infiniti in West Ashley (~15 miles), up to Moncks Corner (~30 miles), and back to North Charleston (~15 miles), zero issues
Yard work Sunday = no driving
Monday morning, problems...

Things done so far:
Tuner says look for vacuum leak,
Charleston Performance Solutions gets me in to pressure test the intake piping. Found both MAFs leaking, fixed that issue. Found a coupler with a small leak, didn't fix yet, but does not impact AFRs since it's before MAFs
Pressure tested the vacuum lines to the boost meter, BOV, and Fuel regulator, solid to 25 lbs, no leaks
Tuner sent me a potential electronic fix via remote tune, but no change
Swapped MAF extension cables

Current Thoughts:
Bad harness - Nope
Bad Gas - maybe? tuned on 93, 0.01% chance I accidentally put 87 in it
Vacuum leak - maybe? would have to be post throttle body and not a vacuum line.

Does anyone have any ideas? Thank you so very much in advance!

UPDATE: MAF sensor abnormality that follows the connector. I have the "gen 2" Stillen extensions on order, arriving Saturday. More to follow.

Another update: Replacement harnesses received, verified <.2 ohms per wire, and they are not the problem. Car seems to be getting worse as it will not even idle for more than about 20 seconds now before dying...
Ironically the MAF connection without the extension reads .2V lower on the 5V supply signal than the one with the harness (4.803 compared to 5.038 with battery voltage at 11.6)