The catalytic converter was one of the greatest emission control inventions in the history of monitoring carbon and greenhouse gas emissions. It starts in the engine, but the catalytic converter is the last stop for exhaust gases and the last chance to launder that nasty air before it shoots into the atmosphere, and our noses.
How It Works, Basically: Your catalytic converter is a magical hot box. Ok, it's not magic, but it sounds magical the first time you hear how it works. Hot exhaust gases exit your engine and head through your exhaust to the catalytic converter. Inside this expanded tube is a massive network or honeycomb of ceramics. This ceramic checkpoint has been coated with compounds that react with the exhaust to eliminate certain harmful emissions. Even though the exhaust is flying through the tube at high velocity, the molecules that coat the ceramics are able to react in milliseconds, hanging on to the bad stuff until it's converted to something harmless (or less harmful) like Nitrogen, Carbon Dioxide or water vapor.