I may be a little late on this one, but are you running an open air compressor bypass valve, if so, this may be causing the car to stall when coming to a stop or while driving and shifting into neutral. I was dealing with this problem on my S13.

 

If all seems well then I'm gonna take a shot in the dark and assume you're running a blow off valve that vents to the atmosphere instead of recirculating it back into the intake. If so, that's your main cause of stalling upon coming to a stop. Keep playing with the Dec. Air. function until it figures it out, it may not be able to since you're already compensating for the largest injector size the AFC can handle.

 

yeah it vents into the atmosphere, but it shouldn't cut the car off. I would understand if it bogs down, but not cut off...

 

get another tune

 

It bogs down and stalls. It depends how much air is being vented.

an SAFC should not be used to tune your car to run larger injectors. All it does is fool the ECU into thinking a different amount of air is coming in. It still uses the existing map in the ECU but just a different location since the air data is tampered. Becauese of this, it uses incorrect ignition timing and your risk damaging your motor in the higher RPMs with more load.

Enthalpy, EFI, Hybrid Dynamics, and Jim Wolf all sell ROM tuned ECUs. They come with a base map for differnt injector sizes and MAFs.