O2 Sensor current?

[Roger Heflin]

On Tue, 23 Mar 1999, Gary Derian wrote:

> 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>
> 
>
The air (at least on my vehicle) is injected in at the headers, so the
air should affect the O2 readings, at least I cannot see how it would
not affect the O2 readings.

I would not think a simple resistor would work either, at least not
that low of resistor, and if they are using a resistor, they are
probably getting both open circuit voltage, and voltage through the
resistor/current through the resistor.   I don't think with just one
you can properly figure out battery charactistics.   

I like the other idea of measuring the resistance of the O2 heater,
and calibrating that to get egt temps.    Then I would need ot get a
pcmcia AD card, and hook that up, and get the aldl data recorder
software working together with that to get one data stream.

			Roger

> > 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
> >
> >
> 
>