I was just curious as to how you are supposed to tune the air/fuel ratio on the car if the CPU automatically tries to tune it real time depending on the o2 sensor readings? Also, is there really a difference between a SAFC or a MAFterburner? I noticed that the MAFterburner has two settings, one curve for wide open throttle, and another if the throttle body plate is only partially open. My last question, is if you have a returnless style fuel system, would you be able to rely on one of those two products to take care of the fuel problems for a car running around 6-7 psi? Thanks alot!