Weird, sudden AFR issue Proform 750cfm!

Fom all your posts it sounds like the car is running good by your seat of the pants meter, but the gauge is showing numbers that indicate otherwise? I'd disconnect it and go back to old school feel. Just drive it for a while, Short of a passage having an aluminum or brass thread shaving stuck or floating around somewhere, or perhaps an accelerator pump cluster experiencing some pullover, dribble? Keep your hands away from your hair, if you have hair that is! Good luck