Since idle only tests cannot pick up defective or missing catalytic
converters, EGR systems, modified engines or other problems that created
excessive pollutnats such as NOx, many areas got the IM 240 tests, otherwise
known as the dynamometer  tests. Keep in mind the '81 came in two different
versions, 49 state and California. The California version got the 2 way
catalyst with O2 sensor and electronic ignition. Since the California Air
Resources Board (CARB) was started before the EPA they are recognized and
can set different standards than the EPA. Other states have to follow the
EPA and most state emissions inspections programs are the result of there
being non-attainment areas.  States can also choose to use the CARB
standards. VW used the fuel injection from 1975 in many of their vehicles to
avoid using a catalyst. VW also avoided EGR for most engines. Most cars went
to the three cat and O2 sensor between 81 and 83 for NOx reduction. This was
the most likely reason for the end of the air cooled engine and probably the
reason the Vanagon never saw the inline 4's.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Richard A Jones
Sent: Sunday, March 18, 2012 6:22 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Catalytic Converter???? Anyone go without it???

I unknowingly ran my '81 Vanagon for several years with a hollow cat.  It
had to pass emissions every year and it did.  With a new cat, it continued
to pass emissions, perhaps with slightly lower readings, but I'd have to
check the records for that.

Of course, it has the bad-mouthed 2.0 l air-cooled engine....

Richard