Yeah, this thread is right -- the car will run without the O2 sensor,
but it really does help.  These were not on the first Vanagons except
the California models.  At $25 each (even more back in 1980) this added
quite a chunk ot the price of a car.  VW doesn't put any extra money
into production unless it is forced to.  Adding the O2 sensor was forced
by the emissions laws, but it really is a good idea, as is most of the FI
system.  This whole closed-loop system is actually much simpler than *any*
similarly efficient carb system.  Most carb systems just waste some extra
fuel rather than get more complex, but look at the horrid carbs that were
on American cars until they were forced to FI.  They really sucked, and
were incredible complex -- all to make the fuel burn efficiency up to pass
smog laws.

Altogether, the latest Bosch Motronic systems beat all the past hacks by
miles, and they get better each year -- simpler, smarter, cheaper and more
reliable.

If you really want to see something awful, look at a really antique car, with
a cotton-wool carb (gasoline was dribbled onto a mat and allowed to evaporate)
and hot-tube ignition.  We've come a long way.

Fix the O2 sensor.  I always tell folks that the California 1980 Vanagon
was the BEST aircooled motor ever in a VW, simply because of the closed-loop
operation enabled by the O2 sensor.  1981-2 and non-California versions 
had that awful EGR system added (thankfully removed as the FI got better).
But look at the Bentley diagrams and see how much simpler the California 
model is -- all by adding the O2 sensor. (pages 24.3 and 24.4)

malcolm