At 07:04 PM 4/11/2010, Jake de Villiers wrote:
>The reason the emissions are higher is because the mixture goes full
>rich. That's why there's a concomitant power increase.

Dear Jake,
No, really, it doesn't.  The European Digijets didn't even have one
-- couldn't, because they were still using leaded gas.  And I drove
Dutiful Passage ('84 Westy) all around Scotland in '91 with no sensor
and no CAT.  When it came to the US (it was delivered in Germany)
VWOA installed the CAT and sensor instead of the straight pipe it was
delivered with.  No change in mileage.

Yours,
David