This seems to be a huge debate on all the forums! Couldn't find a concrete answer anywhere. The way I did it in the end was (don't know if it worked)

- disconnected battery for 4 hours
- depressed brake pedal to kill any residual power left in ecu
- removed engine managment fuse, as I couldn't find a KAM one( removed for 15 mins)
-reconnected and let idle for 20 mins.
- drove on a variety of different roads.


The conclusion was that I had very poor idle when I stopped at lights initially after the new iscv. I no longer have the poor idle at lights, leading me to believe the ecu has accepted the new iscv.

I do have a new issue though since the reset and iscv change. When I start the car I have extremely erratic idle. Idle has never been an issue with the car, I unplugged the maf and the car ran perfectly. So it appears now the issue was a mixture of the maf and iscv.

Be good to get a definitive guide for resetting the ecu though!