1990s13silvia

i have a 1990 s13 ca18det and recently im having a problem since my build ive done 444cc injectors z32 maf walbro 255lph fuel pump fmic and t3/t4 turbo upgrade with a horsham stage 3 chip to compensate for all that and when key is turned to ignition the computer reads code 55 no issues but when started it goes in safe mode and gives me code 12 maf sensor. would this mean i have a bad maf or something to do with wiring the z32? as far as i know the wiring is 12v power black with white stripe to black with white stripe and ground black on loom to orange on z32 then green with black stripe on loom to white on z32 day 8 since build trying to get it running help me please!