I had an aftermarket CAT installed on my 84 GL about 8 years ago.
It was a cheapo. I wasn't too happy about its look. But liked the
price (less than $100). So far it never failed any SMOG test.
I am in the Bay Area. I have no idea what it is all about 
California CAT. My cheapo CAT has been amazingly great. I can
speed up my GL up to 80 MPH on the freeway if there is no head
wind. The CAT is as good, if not better, than the OEM one.

Unfortunately I don't know where my mechanic (my cousin) got
it from. I don't know what brand it is. My cousin apparently
did not make profit from it. He only ordered it for me. I installed
it myself. I don't anticipate it will go bad any time soon.

David

 

--- On Fri, 10/2/09, Robert Fisher <refisher@MCHSI.COM> wrote:

> From: Robert Fisher <refisher@MCHSI.COM>
> Subject: Re: California catalytic converter needed
> To: vanagon@GERRY.VANAGON.COM
> Date: Friday, October 2, 2009, 11:43 AM
> --snip--
> I can find nobody who understands the new CA BAR
> rules.� Evidently there is
> no information about why the old OEM model CAT is no longer
> acceptable, or
> why it's performance is not as good as these new ones that
> are required.
> --snip--
> 
> Local smog guy says: There were no specific regulations or
> specs for the
> cats, so aftermarket manufacturers were skimping so badly
> on the necessary
> ingredients that the cats would only last a short while,
> basically requiring
> the replacement of same every or every other smog check;
> Also, people were
> using new cats as a short-term band-aid to hide fundamental
> running issues
> that would cause the vehicle to fail. The conclusion here
> was that this was
> both a rip-off of the customer and an end run on the intent
> of the smog
> program. Apparently they now require replacement cats to be
> much closer to
> OEM specs, hence the cost. Look for this to become a trend
> nationally
> throughout the jurisdictions that require smog checks.
> 
> Cya,
> Robert
>