if they don't really do any thing and the computer adjusts after a short while why does everyone use them? i have a new holley i'm just wondering if i should use it or not thanks
brad

 

AFPR's have merit for modified cars (i.e. cams, heads, blowers, nitrous) and apply mostly to WOT conditions where the engine runs in open loop mode (O2 sensors not adjusting air/fuel ratios). There won't be any benefit for a near stock engine.