84 vanagon runs great but a little rich for my satisfaction.
On a hot day in August I decide to replace the o2 sensor.  Just
routine maintencnce coupled with the hope that I could get more than
15 mpg.  I chose the cheap route and bought a sensor made in the USA.
Installed it (did I mention that it was hot)  .  Started it up...
hmmm the starter had to crank it 6 times before it ran  (usually it starts
after 1 to 2 cranks).  Hey its running nicely .  I stop the engine for a 
while.  return after 5 min.  The engine will not start!  It's getting
hotter!  Thinking that it's flooded i check the plugs dry as a bone...
hmmm... unplug the sensor .... 10 min. later it starts and runs fine.
What' is going on here... This new sensor scares the hell out of me
I leave it unplugged.  The bus is running as well as ever I will
check what type of mileage I get without it.  Could it be that 
the old sensor (which had 50% of its vents clogged with carbon) was
screaming to the ECU to send more fuel?  Could it be that this new 
sensor is sending really high voltage messages and really throwing of the
ECU?  Anyway the moral of the story I think has yet to be 
determined.
Robert  ...looking for a moral....