Hey sau,
Seems i have stumbled upon a problem before im selling my car. I currently own a RS four S stagea which is the manual RB25DET neo version, My problem i have encountered is under higher rpm roughly 5,000 my car dies out in a way and wont boost properly then when the rpm gets higher it seems to be working properly without the hesitation. This usually happens with spirited driving.
My diagnosis is either my AFM or coil packs but i may be wrong.
Looking forward to your answers cheers.