Another FI O2 Sensor Question, 3.0L FI Bung Location, Muffler or Header?? Options

[ArtechnikA]

...So I've got the data, but I doubt any of it is available in a persistent online archive...

I've got it, but it was easier to just ask - so I did.
I asked if my 1-paragraph was correct. It is. Here's some additional information for background:

" Important thing to remember is - our CIS systems are a
mechanical fuel injection at best. True fuel control is mechanical and
maintained by - fuel pressures and initial CO adjustment.

According to Porsche, they went to the Lambda sensor / TWC in '80 to save
weight. The TWC system drops the air pump and EGR.

The Feds were so suspect of this "non-mechanical" emission system they
argued that the little O2 sensor would shortly burn out, thus dropping birds
out of the air too soon. Bosch said, nein - this is one tough cookie
and can last 100,000 miles. No no said the Feds - but we'll let you bring
in your evil cars if you change out the sensor at 30,000 miles. So a gizmo
went in to the speedo that clicks on the OXS light at 30k and a warning in
the owners manuals states such. Of course this may only work for the Jimmy
Caaarter 85 mph speedos - of which there are probably 7 SC's nationwide
that still have those.

Of course after the Carrera years, the O2 sensor steps up its work load with
electronic fuel control items and now it is the quintessential gizmo that
makes our engines what they are today - powerful and clean.

Oh - the TWC system DOES need a slightly rich O2 level (14.6 to .8), but
that is set mechanically with the stuff on the engine, not the O2 sensor, as
it does today. Oh, and #2, to correctly operate - the fuel control must
operate in a very narrow band. "

So there ya go. I have personally verified that with no sensor, the box itself provides a small, constant, midrange voltage for itself. When the sensor is plugged in, its signal strength overrides the internal reference.

The dithering is done to make the cat bed work at optimal efficiency. No cat - no need for dithering... When I did my CIS-K[e] tinkering, I kept the sensor in part so I could watch the response and verify everything was working. Without it, I'd had to plug the hole in the bung with something, and I had this perfectly good sensor...

[Mike Bellis]

I gave Jeff 2 real O2 bungs and plugs today. That way he can put one in each collector. Plug one and use the other. I would test each side with a gauge and put the sensor in the side that runs the leanest. That way you can keep an eye on it. Let me know if you need a gauge.