I have to fess up.  I don't even have the EGR filter box on my '80 
Westi.  The whole assembly from the muffler to the tin is gone.
Been CA smogged several times, and never noticed by self or 
technician.  Passed no problem.  Now, however with cooling of my 
engine in mind, I am looking for the stuff that goes between the 
muffler and the underside of the tin.  I have the crossover pipe and 
a supposedly functioning EGR valve.  Any bits and pieces laying 
around or sources for inexpensive parts?  I know that I will have to 
get stuff welded back together.

Also I heard that the "filter" really acts to cool the exhaust gas 
more than anything else.  Any comments?
Can I just get a piece of pipe welded/installed without the can?

What does the EGR system do anyway and HOW does it keep the engine 
cooler?

- Jeff '80 Westi

> > Then Steve Johnson remarked:
> 
> >> Wow Lee!  You actually 'bought' one of those?  Every one I've ever seen
> >> is plugged somewhere between the exhaust and the EGR valve.
> 
> > Well,  I thought I had to.
> 
> You know, I just went through all this to get my '78 Westy past CA smog. In CA 
> they definitely check my year for egr function, since my egr was "tricked up" to
> pass visual, but would not function. My egr filter box was basically intact,
> but the upstream pipe was rusted through. I cleaned out the can real well with 
> oven cleaner (the steel wool in there has long since gone away). A muffler
> shop reattached the thing to the muffler for me. A lot of fussing
> with the other components, and I PASSED :-)