Date:         Mon, 21 Nov 94 12:03:17 CST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Joel Walker <JWALKER@ua1vm.ua.edu>
Subject:      Re: O2 sensors, setting air mixture

On Mon, 21 Nov 94 11:54:19 CST Dan Houg said:
>...                    BTW, if you do happen to have a CO meter, it
>is ESSENTIAL to take your reading at the test plug *before* the
>catalytic converter, otherwise you will get low CO values not
>representative of the exhaust.

but this brings up the question: why do all the emissions tests that the
states do stick it up the tailpipe? likewise, the gas tester you can buy
from those folks in florida.

i know that you are SUPPOSED to use the test plug ... and it makes sense
that what you want is for the engine to be putting out the best mixture
possible BEFORE the catalytic converter has to work on it. BUT ...
can we assume that the cat processes X percent and therefor the tailpipe
measurement IS indicative, if only a bit low?

or are the states just being lazy with the requirements?

one of the things i've been semi-interested in trying is one of these LED
indicators. but you have to drill another hole in the tailpipe, weld on an
adapater, and install a 2nd O2 sensor to get them to work ... and their O2
sensor has to be upstream of the original O2 sensor as well. their cost
hasn't helped push me in that direction either. :)

joel