Outer Limits 4x4 Board

Hi All

I have been reading a few 4x4 mags re getting more power from your 4x4. This module is mentioned. I assume it is not a mod chip. According to what i have read they are plug and play and allow you to increase/decrease power to suit conditions. How does it work?

I have a nissan 4.2 TD and would be interested in feedback of the increased performance pro's/cons etc

Thx

it only works on EFI diesels and the 4.2 isnt, so thats not an option. But search there are plenty of threads on 4.2 power ups