Hey - nice work on your research and thank you for sharing it.
One of your old posts talked about running a HE in the rear of the car. Are you still setup this way?
After reading thru your posts it seems ultimately you increased the volume of the system significantly i.e more coolant, larger overall HE area, and high flow pump. Did you use the dual outlet pump - one per HE?
I understand the heat removal is a big thing as that is what seems to keep your sensors cool in working range.
Where are the air sensors physically located?
x-chr
The heat exchanger in the rear did very little on the street. The VW radiator made a difference in all conditions. I am only using the Meizere pump with the h/e/s in a series. The sensors are in the stock locations.