13.) Mismatched aftermarket MAF (Pro-M, Mass Air Systems, C&L, etc) and injector size. The aftermarket MAF must have a matching flow rating for the injectors. If you have 24 lb in injectors, you need a 24 LB aftermarket MAF. Ford OEM MAF's are matched to the computer and the injector size calibation is done in the computer's program. The Cobra computer is an example of this rule for Ford OEM MAF's. It uses a standard MAF and changes the internal tables to modify the fuel curve for 24 lb injectors. Some aftermarket devices can modify a mismatch between MAF, computer and injector size, but they are not very common. Does this mean that i should use my stock 19lb injector MAF instead of the 24lb MAF that i bought? or should i stick with the 24lb MAF?