I get misfire codes (only after i installed my fmic) only if all these conditions are met,
-the car has been sitting for 2-3 days
-it's cold out (40 or less)
-It idles for 2-3 minutes (if i just get in and drive it doesnt do it)
sti, stock plugs, walbro, aps fmic, sz55, perrin injectors, typhoon (yeah, no bigmaf)