MAF; how to adjust richer

[rusty1320]

I have a 2007 Mustang GT with the Diablosport Predator (older 2009 version) which has a performance tune for long tube headers, Vortech blower w/water/air intercooler VR7140. recently bought this car with serious lean condition, misfires code verified. New 42# injectors and 350 lph fuel pump & fuel pressure sensor, new plugs. Now around town and at full throttle runs flawlessly. beautiful idle. Problem is I still get a misfire around 2,900-3,000 rpm and a system lean code. I'm new to this kind of tuning. It has the predator module connected to the MAF sensor under hood. When the MAF change parameters adjustment scale comes up which way do I adjust to richen the mixture?

[mikel]

moving to the right should add fuel.

This is a global change. The tune SHOULD already be matched to the MAF, so IMO this isn't the correct fix here...