Engine stalls when coming to a stop or during long idle... ?
 

I have a 2012 GTR tuned to 700HP (upgraded and remapped with EcuTek) and its been running fine but recently car started to stall and turn itself off when i come to a complete stop or leave it in P or D for a few minutes...

When i come to a full stop at the lights the revs will fall bellow 900rpm and i will hear the prop shaft make a rattle (fairly loud - hope its just a prop shaft rattling...) and the engine looses power and stalls, sometime the revs will jump back up to above 1000rpm and it will be fine but as of today it happened 3-4 times while driving at low speeds around town in 1st or 2nd gear mainly...

any idea what could be causing such issues? map needs adjusting as engine is flooding with too much fuel? O2 or other sensors playing up, inlet related?

Help will be greatly appreciated