catalyst can purify CO,HC,NOx pass EURO2,3,4,5 Our quality management system ... and rhodium, which are used for purifying of unburned hydrocarbons (HC) , carbon monoxide (CO) , and oxides of nitrogen (NOX) form the ... honeycomb density can be 100,200,300, 400 or 600 cpsi . The shape will be round, oval, racetrack or other special .Quantity ...