Originally Posted by BigE3
NOx and what the cat is supposed to do is 2 different things
catalytic converters: Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx → xO2 + N2
Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO2
Oxidation of unburnt hydrocarbons (HC) to carbon dioxide and water: CxH2x+2 + [(3x+1)/2]O2 → xCO2 + (x+1)H2O
If your cat is not working your nox will be high. I just failed an aircare here in vancouver and changed the cat and went back through and passed.
you can check your cat to see if its working by using an infrared thermometer. bring the jeep to operating temperature and check the temp of the pipe going into the cat. then point the sensor right on the cat (not on the heat shield) the temp should be allot hotter. this means the cat is working because there is a chemical reaction happening in the cat and when its working it gets damn hot.