Pre + Post O2s

[Bruce Plecan]

-----Original Message-----
From: Ord Millar <ord at aei.ca>
To: diy_efi at esl.eng.ohio-state.edu <diy_efi at esl.eng.ohio-state.edu>
Date: Tuesday, March 30, 1999 10:59 PM
Subject: Re: Pre + Post O2s

Local gm store has different part numbers for front and rear.
Different basic designs, too (from application to application).
Grumpy


>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
>>
>>
>>
>