Ticking Cat

[240booster]

Why does my catalitic converter tick and click after i drive the car??? What and how exactly does the cat cut down on polution?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>

[LanceS13]

The cat provides an environment for reactions to take place. &nbsp;Gases that come out of the engine include carbon monoxide CO, oxides of nitrogen NOx, and unburned fuel/hydrocarbons CxHx. &nbsp;These gases react with some left over oxygen to make less harmful compounds.
CO reacts with oxygen to form carbon dioxide.
nitrogen oxides decay into oxygen and nitrogen.
hydrocarbon combust with oxygen to form carbon dioxide and water vapor.
I'm gussing the popping is these small combustion reactions continuing after the car is turned off, until the cat cools below reaction temperature.

[S13Grl]

In other words: your cat is hot while you're running the car. When metals cool down, they make a popping sound, and so does your cat.

Thanks, lance! :biggrin:

[240booster]

RIIIIGGGGHHHHTTTT &nbsp;YA THAT'S ABOUT WHAT I FIGURED LMAO &nbsp; THANKS LANCE &nbsp;:-P