I'm running a Lex (w/ screw mod) and 550's...no S-AFC, but I do have a PLX wideband O2, a Walbro 255 pump, and an Aeromotive FPR. Lagged is correct, I adjusted the screw to get a good idle, but other than that, the stock ECU compensated for above idle runs. The wideband shows 14.7 at cruise...