If a three-way catalytic converter is functioning properly, only nitrogen, carbon dioxide and water should be coming from the tail pipe. The byproducts are formed from nitrous oxide, hydrocarbons and carbon monoxide. The secret to the three-way reduction process is the ability of the converter to combine these harmful molecules with oxygen. In this video, Andrew Markel covers the basic chemistry that is happening inside a catalytic converter. Sponsored by Auto Value and Bumper to Bumper.