Just on my way to the ocean to escape the heat,
going up a slight hill on the freeway, when all of a sudden,
a big plume of black smoke started belching out the muffler.
My vanagon started loosing power, almost didn't make it up the hill.
Oil press., water temp., oil temp., etc. all seemed normal.

This has never happened before. My '90 westy with 85,000 miles
has always been totally reliable (even though it's not a Toyota).
I pull over and the engine idles rough and finally stalls.
My first thought: vanagon kaputt (heads, pistons, rings ???)

After the inital shock, I started to think about all these recent posts
about O2 sensors. Hmmm...  As a long shot,
I disconnected the O2 sensor, and lo and behold,
my westy runs just fine (except during acceleration and idle,
there is a slight smoke, like too rich gas mix).
I have a new stock O2 sensor on order now.

Without the knowledge of the list, I would not have expected
a burned out O2 sensor to make the van run so poorly.
Thank you all for this recent discussion. For me, it was very timely.

Harald
'90 westy