At 11:48 AM 8/26/98 -0900, Steven Johnson wrote:
>So here are my questions:
>
>1. Is the O2 sensor that cylindrical object stuck into the end of the
>catalytic converter?
Yep, that's it.
>
>2. Where do you unplug it to replace it?  I've traced the wired into the
>engine compartment and found what looks like a plug junction, but
>couldn't seperate the wires.
>
There should be two plugs--one with two conductors and one with one
conductor If you want to "disable" the O2 sensor, disconnect the
single-conductor connector. This is a spade-lug connector. The other two
conductors are connected to a heating element that preheats the sensor.

>3. Can you run the engine without the O2 sensor?  I ask for two reasons:
>
Yes, The ECU will run the FI in open-loop mode if it detects that the O2
sensor isn't there. Open loop mode means that the ECU will make it's best
guess at the air-fuel ratio without any feedback from the O2 sensor.

>        a. I'd like to be able to unplug it next time it falters and see if the
>problem goes away, and
>
That should be a good first step at diagnosing your problem. There's lots
more information in the archives about further tests you can make.

>        b. If you can run it without it, what's my motivation for replacing
>it?
>
The engine will run better and produce less pollution if the O2 sensor is
installed and functioning properly. The O2 sensor not like an appendix, it
has a useful function.

>4. Ron advertises O2 sensors to replace mine that "require splicing".
>What's meant by this?  The archives seem full of stories of spliced O2
>sensors that don't work.  As someone who's not terribly technically
>proficient, I'm hesitant to attempt to solder and shrinkwrap a generic
>sensor.
>
If you aren't comfortable splicing and soldering a generic sensor then you
probably should just fork out the extra bucks for an OEM sensor. It's really
not very hard though.

>5. Where's the best place to get a stock sensor?  How much should I
>expect to pay?  Is it relatively easy to install a stock sensor?  It
>doesn't look like it would be a huge problem.
>
Camelback VW (800 876-5199) would probably be the cheapest place to get a
stock sensor. Ask for the "Internet discount." I don't know exactly what
they cost, I think that they are over $100 though. Quite a bit more than the
generic sensor. They are pretty easy to install. Liberally soak the old one
in penetrating oil before trying to remove it.

>Thanks for the info, people.  Your advice and willingness to share it
>make owning a VW a much more pleasant experience.
>
Good luck!

MM