O2 sensor idea

[Roger Heflin]

On Tue, 20 Apr 1999, Greg Hermann wrote:

> >On Mon, 19 Apr 1999, Greg Hermann wrote:
> >
> >> >That is why I want to get a well calibrated wide band unit and setup a
> >> >pic or something similar to give the kind of results the stock
> >> >computer wants, and give mv readings that actually mean something.
> >>
> >> As I said earlier, Roger, it MAY (not sure yet) be possible to bias a wide
> >> band O2 sensor with a constant ion pumping current so that it crosses at
> >> any A/F ratio you want, in the same way that a standard EGO or HEGO sensor
> >> does--Changing the bias say for cruise or WOT, and leaving an oem ecm in
> >> closed loop would allow a programmable selection of A/F ratios  for
> >> different operating conditions. (The bias adjustment is what would fool the
> >> ecu, the sensor would act like normal EGO sensor at 14.7:1.) The bias and
> >> its changes would need to be dealt with outside of the oem ecu.
> >>
> >> Regards, Greg
> >
> >The idea is to bias the wide band O2 normally so that it reads the
> >range of AFR that you want.  Then put a pic in front that inputs the
> >wideband O2 sensor voltage,/other info and converts that via a table
> >(non linear table to make the wb act like a normal O2 sensor).
> >
> >I guess the other idea is to adjust the bias to read the AFR you want,
> >and then let the computer run in closed loop mode (even at wot), just
> >with the modified AFR ratio required for max power.
> 
> And also with a modified AFR, as desired , at light loads, for best cruise
> economy??
> 

Yes, probably switched off of TPS or in some similar manner to the
stock computer, between optimun economy and optium power.  It sounds
like you could make a stock ecm run correctly with a wide ratio O2
without too much extra work.

Where is some good documentation/application notes for a wide ratio O2
sensor?

				Roger