| Not really hear to have a debate and I'm not a expert but do know a little something about this stuff. Keeping it friendly... Hot cats may help burn some excess hc but the main function of the cat is to reduce the nox, not control hc. CO2 doesn't matter and I don't recall the affects of a bad cat on CO. But what I do know is that a good running cat will use up the oxygen and keep it close to zero. In a perfectly running car the low oxygen indicates the cats are doing their job and when there are O2 sensors after the cat then you should see very little reaction out of them. On a OBD II car when the car senses too much reaction meaning excess oxygen in the exhaust a code will be thrown for it catalyst inefficiency (P0420). Looking at his O2 levels and the amount he failed the NOX by, I conclude his cats are likely bad. The O2 is not high but it's not low like it should be. The HC looks great which means his injectors, and 02 sensors are working as they should and because of that he likely doesn't have any major vacuum or boost leaks.
 Grammar. The difference between someone knowing their shit or someone knowing they're shit.
Capitalization. The difference between helping your Uncle Jack off a horse or helping your uncle jack off a horse. |
