Hi guys. New mustang owner here. I don't understand the concern with the afr. I was always under the assumption that 14.7:1 is ideal.
2014 DIB Premium 3.7L MT82 Pony Package
MPT 91 Tune, BBK Chrome Longtubes, BBK Offroad X pipe, 14" Vibrant Resonators, Airaid CAI, Shelby Short Throw Shifter, 3.73 FRPP