I have always been under the imression that the converters job was to reduce hydrocarbon emissions, unburned fuel. however, now that i think of it, a pre-converter used on stangs was placed there fore the reduction of oxides of nitrogen.....

i also learned palladium was the major catalysts used in modern converters, up untill very recently when ford got a deal that was too good to be true, and bought ALOT of it....then a new and better metal was found....tried to find the link, but not having any luck

also, i was under the impression from things learned long ago, for which i have no source (urban legend?) that the egr's only purpose in life was to lower combustion temperatures, and thus lower NOx emissions.

 

The main benefit of the cat is just like in the fire boxes I used to have...
it basically is a "re burner" in that it is superheated and at such elevated temps it burns up the fuel coming into it more completely...

ON one of my old fireboxes, the cat was on top under a hot plate that once it had the air flowing thru it and up the chimney ther was enough draw to be able to take off the hot plate and look at the cat while at temp....

Pretty neat ! SO HOT it was PINK - cherry red !!!! and no smells even would come into the house ! and I NEVER saw smoke come out of my chimney once the cat was up to temp...