Catalytic Converters for 20V Avant

[George]

Keep in mind that California has led the nation in emissions standards.  The
problem that has developed, as I now understand it, is that a flood of
really cheap CCs came onto the market with the effect that they burn out
after a few months and become "gross polluters" with unacceptably high
carbon emissions. This new CA law, effective January '09, clamps down on
manufacturing standards. A qualified aftermarket cat must meet the standard,
have one half inch high lettering stamped on the can, and can only be
installed if certain criteria are met. The other 49 states don't yet have
the same requirements. So, OEM cats are legal as the standard applies only
to aftermarket cats. In looking at pricing you quickly see the cheapos are a
couple hundred bucks less than CA qualified cats. My wrench tells me the
critical precious metal contents in cheapo cats are much less than the OEM
cats.  Also, as a few have testified here, the original OE cat will go for
many miles. I got about 280k miles on mine. 

Bottom line - Overall the best deal in California is probably the OE cat, if
you intend to keep the car. If not, buy a qualified cheapo, if you can find
one, smog the car and sell it within two years. 

http://www.car-sound.com/04basics/04california_install.asp

On to the 200/20 valve check engine light issue.  Many of these cars in 90
and 91 shipped without the check engine light bulb installed. Everything ran
fine and they even smogged without an issue. And, Robby is right - pulling
the motor fuse will dump all codes and reset the ECU prior to ODB2. 

Last year my '01 allroad failed the smog test because the check engine light
came on. We replaced 2 of the 02 sensors and noted that the code came up for
the torque converter. We cleared all the codes and took the car directly to
smog check. Because the check engine light was not on, and the mechanic did
not hook up to the OBD2 plug, the car smogged just fine. The Check Engine
light is now on because of the leaky seal in the TQ. I have an ODB2 reader
and can use it to clear the stored codes. The question is; will the mechanic
hook up the ODB2 next year and see the stored code for recently cleared
issues. 

George Sidman