Just wanted to share my input on the problems you guys were mentioning. I've been through all the issues you guys talked about, jerks at idling, idle hunting, car stalling etc. My rpm at idle hovered between 500-600. Esp at low speeds driving around car parks, reversing, my car has stalled on me, rpms have fluctuated all over the place. I've had JB4 on and off my car before too, and map0/1/2 DID NOT work well with my car. I'm running PPK stage 2, ar dps, cpe cp, eisenmann exhaust, intake.
To help those facing these problems, go to your dealer and get the whole car's software/electronics/dme updated. It took about 2 days for my dealer to reprogram everything, now the car has never stalled on me again, no idle hunting, and my rpm was increased to 700/750 at idle. The problem with the stalling or idle hunting was mainly due to the rpm being too low, and load. I've not reinstalled my jb4 yet but intend too, along with an fmic, and probably update you guys again.
Hope this might help all who's facing these issues! (: