Tom,
   You have an interesting problem that you should
approach by making this look more like the california
version.   I would start by putting the o2 sensor in
front of the cat.   Perhaps you can make it to the
junk yard and find a part there.   You may have
additional problems but start by making it more like
the california version?   gary
Date:    Tue, 7 Sep 2004 19:14:33 -0700
From:    Tom Young <tomyoung1@COMCAST.NET>
Subject: Do I need a HEATED O2 sensor?

Hi all:

For many years I've been using the O2 sensor in my
California Vanagon
to
adjust the basic air/fuel mixture; that technique has
worked fine.

When I rebuilt my Federal Westfalia (no O2 sensor) I
installed a
water-cooled catalytic converter in the exhaust.
Since the
water-cooled
converter has the O2 sensor bung I figured I could
install an O2 sensor
here
to adjust air/fuel mix.

The first time I tried it I was getting readings so
low (indicating
"too
lean") that I couldn't believe it; the van was running
well and
screwing the
adjustment screw all the way in basically had no
effect on the
readings.
Since I was using an new O2 sensor the only thing I
could think of was
that
the O2 sensor wasn't getting hot enough as the
catalytic converter has
a
much larger diameter than the crossover pipe, thereby
cooling the
mixture.

Accordingly, I installed an 18mm spark plug
"anti-fouling" device in
the
exhaust in the crossover pipe.  The only thing is,
since the
anti-fouling
device is quite a bit longer than a standard O2 sensor
bung (couldn't
seem
to find one locally) the O2 sensor's tip is not fully
in the crossover
pipe.

Again, the readings I was getting from the O2 sensor
(new sensor,
remember)
were extremely low.  Since I just failed my Smog today
(too-high HC,
too-high CO) I know these readings aren't correct.
Again, I'm
*guessing*
that the problem is that the O2 sensor isn't getting
hot enough, since
the
tip is not fully in the flow of the exhaust.

So, I'm thinking I should buy and install a *heated*
O2 sensor; if my
problem is that the single-wire sensor isn't getting
hot enough, that
should
work, right?

Or am I missing something else here?

__________________________________
Do you Yahoo!?
New and Improved Yahoo! Mail - 100MB free storage!
http://promotions.yahoo.com/new_mail