NOX is caused by high combustion temperatures.  Advanced
timing, too lean mixture, bad EGR perfprmance, bad cat all
lead to it.
Tom
----- Original Message -----
From: "Todd Last" <Rubatoguy@MINDSPRING.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, April 12, 2004 12:35 AM
Subject: '88 Failed Smog check

> Hello,
>
> I have a 1988 Vanagon with 168,000 miles that failed the
Oregon Smog check.
> I'm looking for suggestions as to what might need to be
done to get it
> into compliance.
>
> The measure that was off was NOx emissions  (max 4.62
/mi  - Measured
> 8.88 g/mi)
>
> I did have the "performance chip" installed in my ECU at
the time, and
> have since replaced it with the stock chip.
> Any other suggestions as to what I might check before I
take a second
> try at it?
>
> thanks
>
> Todd
> '88 WEsty