O2 Sensor current?

[Gary Derian]

Wouldn't you want to operate leaner than stociometric for better economy?
The AIR should divert to the cat when warm and not affect the O2.  Part
throttle ping can be caused by insufficient EGR.

I don't think a simple resistor in series will work as you want.

Gary Derian <gderian at oh.verio.com>


> I have been trying to see what my O2 sensor draws for current.  For an
experiment, (
> I am trying to make it run slightly richer across the board ) I installed
a 10K
> resistor in series with the O2.  At idle with or without the 10K I read
.57 idle,
> hot, closed loop.  That seems high to me.  If I rev it up, the voltage
drops to
> closer to .4 to .43.  It is somewhat stable, not swinging like I expect.
Is this a
> sign of a bad O2?  I am using a DVM to measure.  It is an GM O2 sensor.
(BTW, I have
> swapped O2 to another from my 91 Bonneville and have no changes)
>
> What I see is a 1.5mV drop across the 10K resistor, and when I rev it, it
increases
> to 22mV.  This is a very small amount of current, it this to be expected?
>
> Can someone give me some advice on this system?
>
> The car is a 85 Cutlass, CCC, 77 Olds 350.  The AIR and Cat have been
removed (reason
> I am trying to richen).  The car runs pretty well.  But when hot there is
a nasty
> part throttle ping, light throttle, when at WOT or heavy throttle, or at
very light
> throttle, no problem.  I have been told that if the AIR system is removed
this will
> cause it to be lean, as the O2 is expecting a certain amount of air to be
present, so
> it would lean it out then.
>
> EGR is working properly.  I am using an 82 307 intake with the improved
EGR tube
> extensions.
>
> Am I missing something obvious?  Will the AIR removal or missing Cat cause
this
> problems?
>
> Thanks for any help!
> Tom Martin
>
>