O2 voltages

[Programmer]

Here's one for ya--is the O2 really for keeping the engine AFR corrected,
or is it to keep the fire burning in the converter ? Which does the EPA
feel is more important--which does the manufacturer feel is more important ?
I'm just throwing this out for wideband comment...
Lyndon.
-----Original Message-----
From: Bruce Plecan <nacelp at bright.net>
To: gmecm at diy-efi.org <gmecm at diy-efi.org>; diy_efi at diy-efi.org
<diy_efi at diy-efi.org>
Date: October 2, 2000 11:00 AM
Subject: O2 voltages


>
>These are my observations and first impressions, and as I distill things,
>and get more time with the WB I'm sure they will be revisited, and expanded
>upon.
>One thing that I'm totally clear on now, is how useless the oem gm O2
>sensors are, for anything other then their intended use (as being rich /
>lean, switches).
>I was able to run the WB on several cars, with several different monitors,
>and watch the displays.
>With all the filtering averaging etc that the ecm and scanners do, there is
>time delay from when an event happens till when reported, and datalogging
of
>what the ecm is doing includes all the filtering.
>
>What's this really mean?.
>You still need to know tuning, and tune up.
>When using the oem O2 for tuning, your quessing,    it will just
>****reliably**** tell you something when there is a major problem, and
maybe
>the magnitude of problem, ie the oem sensor voltage dropped to .3v during
an
>event,   and the WB showed just slightly richer then room air!.  *****So*
>what* looked* like* a* reported* leanness* (with the normal data logging
and
>scanner) was* actually* an* ignition* event*....
>
>The actual output of the oem sensor is nothing like the output of the WB as
>far as resolution of cylinder firings, as far as variance in cylinder to
>cylinder.
>
>I'd also wondered why GM went to watching crankshaft accleration rates
>rather then synching the O2 to cylinder firings, well the above covers why
>you can't do it.
>
>Oem ones work excelent for what they are designed for.
>WB's **can** be an excellent assist, to monitor trends in what you engine
>like *relative* to performance evaluations,  and report back to you what
the
>engine ****LIKES****.
>ie.  if it runs EXCELLENT (best), at 12.25 AFR, then you know, 10.75 is
just
>wasting gas.  Just getting back to doing what the engine *wants* rather
then
>you wanting it to run at xc.y:1 AFR cause that's what you think it needs.
>
>The old saying of speed cost money has taken on a new meaning if you want
to
>solely rely on electronics to avoid having to learn much about tune-up.
>
>Now, if ya think about the above, and how it applies to the world as we
know
>it many things get clearer.
>
>Hope ya'll find this as interesting as I do.
>I ya don't want to hear about it lemme know.
>Bruce
>
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