Service manuals are out there. I do have one for the z6. I tried to upload it but no joy. For the z6 it is O2 ecu pin 24 O/W wire. For IAT it is pin 6 Y/GR. Hard to see second color but yellow for sure. Let us know how the tuner works out. I did look into one of these but seen it as a gamble. When I changed my plug, it showed I am running a bit lean.