O2 sensor idea

[Greg Hermann]

>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?

You can start out by doing a word search on <UEGO> at SAE.org. There is a
paper by some NGK guys on their sensor and its function. covers the theory
reasonably well.

Greg
>
>				Roger