They do a dyno; also, the test only stations don't do a pretest per se - a test with them is a test and it all goes in the computer to DMV, so that's why it's better to get everything looked at and tuned up and go elsewhere to have a pretest before you take it to the test only.  

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
Of Dennis Haynes
Sent: Wednesday, October 20, 2004 6:19 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Test Only Center BS

I'm curious, what is the down side to not passing the emissions in CA?
They have to give you time to perform the repairs, don't they? Any shop
with emissions equipment should be able to do a pre test for you. See
what you got. The concept of getting the cat hot is only helpful for
excessive hydrocarbons (HC). Any unburned HC indicates a problem such as
leaking valve, lean miss fire, ignition miss, incorrect ignition timing
etc. Excessive carbon monoxide (CO) is a mixture problem. Is the test a
dyno test? Then you will have to worry about oxides of nitrogen (NOx).
Incorrect ting, excessive combustion temps, or bad cat. The Vanagon does
not use EGR to reduce NOx so timing and the cat is critical.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Wognacious
Sent: Wednesday, October 20, 2004 9:08 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Test Only Center BS

Listies,
I have an 85 Westy and got my registration renewal in
Arnold's California and it too has a Test Only Center
requirement for my smog test. First time that's
happened and I want to know what I should/need to do
to ensure that I pass. Meaning adjusting the timing,
putting in the fuel additives etc, etc. I've got a
pretty clean running engine, I think, but I don't want
to go through any hassles. Is a pre-test available at
test only centers? I'm pretty sure that if I have the
time I could get the CAT hot enough to burn off any
bad stuff, do they give you that kind of time? Any
experienced help would be greatly appreciated....
TIA,
Paul Rogers
85 Westy Weekender, I think