goes to a seperate pin on the ECU Pin 9 so has to have hardware changed aswell.

no just a plug and play job.

im not 100% if it alters the map signal or simply the signal to pin 9.

I havent looked into it that much, just make the things. dont car how they work

so it might just be a 0-5v signal to pin 9, and the potentiometer adjusts the voltage accordingly, and then the ecu map is altered accordingly.