[s-cars] Emissions Question (NTC- no turbo content)

[R. Mair]

As an emissions tech here in Pa. I can tell you a little more about your
20v... as I had one myself that ran a little high on HC. HC stands for
Hydro-Carbon. Excess HC is essentially unburnt fuel that has not been burnt
properly by the normal combustion process on your engine. Most motors will
have a little excess HC, even the newest VW's, Honda's and other 'efficient'
cars, however once most HC's reach the cat, they are then ignited and sent
out the tailpipe as water vapor and CO. The cat can easily be overwhelmed by
excess HC or even raw fuel which in turn heats up the cat to dangerous
levels and eventually will damage it. This is usually only caused during
ignition misfires.

There is no magic way to get around high HC's if there is a problem in the
engine management circuit. 20v nt's weren't the cleanest Audi ever produced
and do have difficulty meeting some of the more stringent emiss. tests in
this country. What Rich said earlier is prob. the best advice to be given,
short of the dry gas idea. I don't like using that stuff for any reason
except in major winter emergencies. Make your yearly emiss. test a good time
to tune the car up, change oil right before going for the test, and it does
seem that the highest octane gas will work to lower HC's. Run a tank of it
before topping off for the test. I also don't rec. raising the octane any
higher through additives though. You can go too high and actually cause
other failures, like high CO. Good luck, and hopefully this was all a
software glitch in CT.

Rolf

02 Allroad
94 UrS4
90 90 20vt
still looking for a TDI