Hello,

In Phoenix we have something called smog dogs which check tailpipe 
emissions as you drive by.  I think that they are still quite experimental 
and they don't generate citations, but perhaps, a letter of warning.

My question is how can this possibly even work?  It's just not the same as 
a probe stuck up the exhaust pipe.

BTW, I have only seen them on freeway exit ramps.  Our FI cuts off all fuel 
during that type of deceleration, so it is unlikely that a smog dog would 
ever catch a Vanagon poluting in that location.

Mike