Pre + Post O2s

Shannen Durphey shannen at grolen.com
Wed Mar 31 05:47:09 GMT 1999


Been scratchin' at the brain...
Pretty sure that pre and post O2 sensors on the 96 pickups had
different part nos., and different connectors. Will try to verify in
the next few days. Not saying all cars are the same. If so, may imply
something.
Not much of a chemist...but end product has lower HC reading, lower
"fuel" content, would say lower calorie content.  As far as temp of
exiting gasses being lower, not sure I agree. Heh heh... call it the
"burned arms" data collection system.:) Rear O2 readings are very much
like tired pre-cat O2 readings.  Whether or not sensor is accurate,
larger peak to peak differences are a sign of a failing converter. 
We're not looking for stoich, just activity.
Just some O2 sense worth ; )
Shannen
Ord Millar wrote:
> 
> I am pretty sure that the pre and post O2 sensors are the same part on my
> car - at least I can't tell any difference externally, and may have
> accidentally swapped then at one time or another.
> 
> -----Original Message-----
> From: Bruce Plecan <nacelp at bright.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Tuesday, March 30, 1999 9:08 PM
> Subject: Pre + Post O2s
> 
> >As I understand things, the cat converters are a reducing chemical
> reaction,
> >so
> >they consum calories to react.  (True or False?).
> >
> >The rear O2 sensor would run cooler then the front.
> >
> >So, the rear O2 in order to measure the effectiveness of the cat would need
> >to
> >operate at least at the same temp as the front.  So it would need a
> "better"
> >heater.
> >
> >Since it might not track the front too well, then it's "range" would need
> to
> >be greater.
> >
> >Only have any documents to compare the above to, or does it make sense
> >to someone other than me?.
> >Bashful
> >
> >
> >




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