Cat...

[Gary Derian]

1300 PPM is pretty high.  My engines, with carburetors <ducking>, run 100 to
125 ppm without cats.  You should be able to get below 200 PPM by leaning
the mixture and perhaps retarding the spark a little.  Then the cat can
reduce it further to near zero.  The tube in your cat is precisely for
pumping air into.  The first portiion of the cat is for reducing NOx and
operates best anaerobically.  The second portion is for oxidizing HC and CO
and works best aerobically.

Gary Derian <gderian at cybergate.net>
>
>Interesting comment---  this cat has a tube for air injection ...   what if
I
>pump air into the thing?
>
>________________________________________________
>  Kevin Vannorsdel     IBM Arm Electronics Development
>    408-256-6492                Tie 276-6492     kv at us.ibm.com