Excessive NOx is the result of over advanced ignition timing along with a
bad Catalyst. The fact that our Vanagons do not have exhaust gas
recirculation (EGR) adds to the problem. NOx production is the main reason
we have reduced compression ratios and other engine inefficiencies. It is
the pollutant that makes engine and other drive line swaps an issue. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
David M
Sent: Tuesday, June 21, 2011 3:39 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: The Dreaded Emissions test

My van�(1987 Wolfsburg) failed the emissions last weekend. Failed on NoX
(2.75 when limit was 2.5), easily passed the other 2 tests (forget what they
were). Cat converter replaced 2 years ago (cheapo $500 generic unit). I
found a German specialist repair shop about half a mile from the testing
station and they tinketerd with it and got it through. They mentioned they
replaced the�air filter and adjusted something else. They repair guy said
the testing person can fail your vehile just by driving it a certain way on
the dyno. He also mentioned he enquired and the turnover at the testing
station is very high so no-one is very experienced there. Usually with the
Vanagon, they have to ask where the engine is!
�
-David (Tempe, AZ)

--- On Sat, 6/11/11, Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:

From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: The Dreaded Emissions test
To: vanagon@GERRY.VANAGON.COM
Date: Saturday, June 11, 2011, 5:57 AM

While emissions tests suck their main purpose is to identify gross polluters
and you are definitely there. You have both a mixture problem at idle and
one or more ignition, injection, or valve loose head problem. If all is well
with working catalyst those readings should be near 0. Without or before the
cat O2 should be below 1.2% and HC. Well below 200. Dennis Sent from my
Windows Phone