Just thought I would restate my thought to get at the real question a bit better.  I was not really thinking about the Subaru swap thing at all ( which this thread has turned into)  I was really just contemplating the seemingly large differences between the engine control systems in the two vehicles.   Why are the vanagons so sensitive?  Who would build a machine which could be crippled by one sensor malefaction (temp, oxy, throttle position switch)?   Or is it that the sensors in other cars (Subaru for instance) are so much more durable?   A follow up to this thought/question is this:  Are the Audi's fitted with the same sensors?  Do they suffer from chronic electrical malfunctions?  Sure the engines may be bullet proof but who cares if the electronics suck?  And what of the VW inlines?  
Just wondering aloud.
Nat