Understanding STFT/LTFT Logic

[Water]

I’m learning and trying to tune a stock car with just a resonator delete.

Intake is completely stock, down to the airbox.

When I idle, the vehicle would stumble/stall a bit and my physical interpretation was maybe the resonator delete results in less back pressure so the fueling at idle is slightly off.

I have MAP tables activating at -14.7 psi. So if I understand correctly, it wouldn’t be the MAP fuel tables since idle is columns 1 & 2. So I increased the AFM calibratiom by about 10% in the 1.15-1.20V range.
I restarted the vehicle, no stumbling while idle, less surge, it actually catches the rpm’s and seems to operate like stock.

However the STFT is anywhere from +20 to +30%
And the LTFT is around +10%

Everything has been tested while at idle. If I try to add fuel to MAP columns 1-2, it pretty much floods the combustion and the car stalls which doesn’t make sense to me because the MAP is reading less that -14.7 in those ranges so shouldn’t the AFM be determining the fuel?

Is idle controller by the tables or the AFM?

Am I not understanding the use of STFT and LTFT here?
Should I just focus on STFT and LTFT at part throttle only and not worry about STFT and LTFT as long as the vehicle operates properly/smoothly?

[Spunkster]

Without the calibration and datalogs made with them showing the issue it is hard to speculate on what the issue may be.