sr20 running rich problem

[DailyDrivenSR]

I Have recently bought an z32 maf and a apexi neo need help with settings of it 2 in 6 out and i cant setup the low throttle. But can setup high throttle. Maybe the tps is going out. Do to running the neo it idles nice but does not perform as well. When driving. Back fires alot and the setting are to the max almost for taking out fuel. Im running everything stock besides and upgraded turbo and the boost is set on 7 psi. thinking i need to replace o2 senor but just need help before i spend 95 bucks on new one