I have bought stainless O2 sensor bungs for my Etops. I have read about installing them in the tails...Dustin Whipple actually recommended it because they are easy to remove and send out. My question is, is that the best place to install them? or would the header collector be a better place? It would only be about 2.5" difference in position, being one side or the other of the rope seal flange, as you have to have access to the inside of the collector or tail to weld the inner jacket. I know the farther away from the water dump the better...and the headers are already off.

Maybe I am over analyzing it?

Mine our mounted in the location you mentioned in the tails and works fine. 2.5" is not going to make a difference after the collector.

What guages/controller are you using?

Aem

I bought a set of Innovate gauges but found that they need constant re-calibration. Ended up going with AEM...