Re: More on the lambda

[Brett Dikeman <brett@pdikeman.ne.mediaone.net>]

>downstream and clog the mufflers.  Meanwhile, all that heated raw fuel makes
>for neat flames at night, which combined with red hot turbo temps, fries the
>O2 sensor, as well as the muffler filling.  Sound expensive?  For both the

>to fuel mixture.  Certainly agree that this is a crude weapon, given an OBD
>system.  But, I also agree that a EGT is slow, in fact, maybe too slow to be

OK, here's a couple things I'd like explained.  I just took apart my O2
sensor completely.

For those of you that haven't taken one apart, if you disassemble the
sensor, there is a very thin rod that has 3 gold-plated areas for the
heater+sensor.  These connectors then mate with three connectors that go to
the outside of sensor.  A cover goes _over_ the rod and _seals_ against the
case of the sensor.  I don't think the cover has anything in it, because I
don't see any conducting areas on it.  Looks just like a piece of ceramic.

This means that the sensor rod is COMPLETELY sealed from exhaust gas, which
would lead me to conclude that O2 sensors are nothing more than high
temperature senders.  I think the "heater" is to simply help get the O2
sensor up to about-egt temperatures quicker.  You can see the heater
element in the thin rod...it zig-zags the length of the sensor all around
it.

What this doesn't explain is why the sensor is so sensitive to
contaminants, since the thing has that nice cover.  It also doesn't explain
why the sensor would "swing" very much; that ceramic element would take
some time to heat up+cool down.

Can someone help me out here?  I'm confused.  Is that "cover" really the
sensor element?  That seems impossible since there aren't any electrical
connectors!

Brett

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Brett Dikeman
brett@pdikeman.ne.mediaone.net
~)-|
Hostes alienigeni me abduxerunt.  Qui annus est?
Te audire non possum.  Musa sapientum fixa est in aure.
Ita, scio hunc 'sig file' veterem fieri.
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