[Diy_efi] O2 says rich, car runs lean..

[C. J. Frederick]

All great info.  Begging your indulgence on your topic, I saw an O2 dash
display at a race last month.  It was in a Buick Grand National and when
the car was idling, it updated a few times a second.  It had a blue
digital, 3 digit display and was built into the dash.  The owner said he
didn't know anything about it as it was in the car when he bought it.  He
thought it was originally made for an import.  It wasn't a multi-function
display with data logging, just a simple constant reading, rectangular
readout.  Anyone ever see one of these?  I have searched all other sources
known to me.  
Sorry for the interruption,

CJ

>On Sun, 11 Jun 2006 15:45:28 -0700 (PDT), David Rowley wrote...
>
>First of all I have to say that tuning with a narrow band O2 sensor is
>useless. I've been tuning for almost 7 years not and have to constantly
>educate people about the inaccuracies of narrowband sensors.
>
>Second, your readings may be related to the position of the O2 sensor.
>If you overheat a narrowband they will frequently read rich when in fact
>you're running lean. This too can sometimes be caused by an ignition
>timing issue too much retard will over heat the sensor as well. If you
>accidentally put it after a cat then that too will cause incorrect readings.
>
>My suggestion is to replace the narrow band with a wideband that also
>has a narrow output. This way you can have a proper temp-compensated and
>accurate O2 reading converted to narrow band plus have a proper mixture
>display on the dash. The 383 should like somewhere in the 13:1 under
>power and should run just fine in the low 15's under cruise. If you
>properly balance all 8 cylinders with a pyrometer you can run it leaner
>without any ill effects for fuel economy.
>