the 2 wire versus 3 wire thing doesn't make sense.

your 87 vanagon sure should have 3 wires..
one is the signal wire ..
the other two, on a separate two connector plug,  are for oxygen sensor
heat.

if someone said you only have two wires on your 02 sensor perhaps they were
looking at that two wire connector, and didn't see the other one ..
it has to be there.

if the cat is tired ...
it may be, and I have read of many vans that only passed after a new cat was
put on.

I often find the idle switch not making contact, and timing too advanced ..
so check those for sure.
you also want it as hot as you can get it for any smog testing.
like don't shut it off before the test...
you want it running, and as warm as you can get it.
if it's running too cool due to a thermostat not working right, fix that for
sure.

you might say what state, to enhance the general knowledge base for vanagons
and smog checks.

lol..
funny how people often don't say 'where' .
I can find websites for businesses now that don't say what state their
business is in.

What I notice is *it's different everywhere* ...........
therefore *where* we are talking about matters a lot !

it's VERY different everywhere actually.

----- Original Message -----
From: "Sallye Clark" <sallyeonlake@YAHOO.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, September 17, 2010 11:40 AM
Subject: Emission test on 87 vanagon

We are having a problem with emission test for our ve. It seems we have an
aftermarket02 sensor with only 2 wires instead of 3. We have been advised to
get a new catolitic converter and get another o2 sensor. Expensive and lots
of work. We have tried adjusting the engine useing an adative and it varies
from pass to fail or fail to pass but not pass pass on both areas
the first fail was in idle and only off 5 points(too high)
HELP any ideas??
Sallye and Pete Clark