Eractic O2 sensor

[Andy Lawrence]

Ken Kelly wrote:

> Andy,
>         Your readings are correct and accurate. The standard O2 sensor really behaves
> more like a switch than a linear scale. Your PCM/ECM just looks for it to switch
> accross the 14.7 to 1 voltage. As soon as it crosses the ECM starts to force it
> the other way while it is in closed loop. That means that in closed loop (read
> part throttle) it will oscilate back and forth at a fast rate. At Wide Open
> Throttle it goes into Open loop, and tries to set the AFR to about 12 to 1
> therefore the ocsillation stops.
>
>         You really need a wide band O2 sensor to get good readings. Some people claim
> that with adequate damping you can get a sense of the AFR from a standard O2
> sensor. You obviously don't have enough damping in your circuit.
>
>                 Ken
>

I put a small capacitor in the curcuit and it did calm the ocsillation a bit!

Thanks for the help, my engine is modified and i think that it is running a little lean!
I am trying to find a way to richen it up without having to burn another EEPROM.  Do you
have an sugestions?  I was thinking of trying to up the fuel pressure about 1 or 2 psi,
do you think that would help?