Hi all,
This is just in case someone makes the same mistake I did.
I wanted to make a reasonably long lead between the sensor and the unit. I figured that I needed decent cable for the power, but not for the signals.
I therefore used thin shielded wire for 4 of the wires and heavier gauge for the two power lines.
I bench tested this and it work fine. When on the car though, the temperature jumped between two numbers (765 and 815 I think) and the AFR stayed at 1.36 (or some other very lean number.
My mistake? I assumed that red & black were the power lines - they are not. Yellow and White are.
I changed this, and it’s all running nicely.