Dennis,
Its my understanding after discussing with my mechanic that the outside air
temp may make a large difference on the NOx when you take your vanagon in
for smog check.
A 100 degree day vs. say a 30 degree day.

Doug

----- Original Message -----
From: "Dennis Haynes" <dhaynes@OPTONLINE.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, September 09, 2005 5:50 AM
Subject: Re: NOx high

> NOx is caused by excessively high combustion temperatures. Usual causes
> are a lean fuel mixture or over advanced ignition timing. Since the
> Vanagon does not use EGR, the engine settings are extremely critical.
> The Cat has the major job of reducing the NOx and all aftermarket cats
> do not have as much active material as the original so they do not last
> that long.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Mike Miller
> Sent: Friday, September 09, 2005 12:09 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: NOx high
>
> Vanners,
>
> My van passed smog but the NOx was just below the maximum. New cat two
> years
> ago.
>
> Any likely causes to look at?
>
> TIA
>
> Mike