EGR and emissions problems

[Berkeley and Bill Conner]

Ari wrote:

> I'm having trouble getting my car to pass emissions (roller test).  The
> problem is that I'm not getting any vacuum
> to the EGR valve.

Stating the obvious, you need to cut the HC and NOX emissions by at least 50%.

I'm no expert, but I've heard that high NOx is consistent with EGR malfunctions,
and it sounds like you may need to clean the BPT tube.  This is a common problem
with a high port engine (is yours pre-1994?).  Check the little 9 inch metal
tube with multiple bends that runs from the BPT hose down to the EGR pipe that
connects to the exhaust manifold.  It's hard to clean because it has a only a
small hole at the bottom end of the pipe.  And you really can't see it.  You can
check SE-R.net for instructions on how to clean this -- but pressure from this
tube is what activates the EGR system.

Another thing that you might try is retarding the timing a few degrees.  This
sometimes reduces emissions overall.

Please post updates on your progress, I'm about to test in MD with my S3s for
the first time.

Good luck,

Bill Conner