My STFT's are cutting as much as -30% and my wideband is still reading between 11-12.5. Runs good. Before I installed the Cat and muffler the AFR reading was almost dead on 14.7. I had about 18-20 inches of 3 inch pipe downstream of my wideband initially; I don't believe I was getting air at the o2 due to the short length. Mute point now, exhaust installed, running rich at idle.
Lq4 with flat top pistons
3" long tube headers and 3" dual exhaust
TS cam 212/218 .550 lift 112 lsa
8.1 delphi fuel inj (42lb)