Eractic O2 sensor

[Andy Lawrence]

Hello

    I have built Dave Morrill's O2 sensor on the efi332 web site, hooked it up
to my chevy truck.  At all throttle positions except full throttle the reading
on the O2 sensor meter is extremelly eractic.  It moves from 1 to 5 faster
than i can see it! But while at full throttle the reading is consistant at 5!
Why would it be so eractic off of full throttle?

I know that the O2 sensor is working properly because i hooked it up to a
variable supply and ran though the 0 to 1 volt range watch the light count by
the .10 of a volt....

The O2 sensor and the throttle position sensor are both pretty new.....

thanks