Catalytic whatsamacallits?

The year is 1974, there is just a basic understanding of how important the environment is.  Just five years removed from the Cuyahoga catching fire, and 4 years removed from the first Earth Day, but still 4 years aways from the horrors of Love Canal, and 5 years away from a nation being terrorized by Three Mile Island.

A small device makes its debut from General Motors Corporation in response to the Clean Air Act of 1970.  It has the inauspicious name of the Catalytic Converter.  But it will have a very big future.

So what does a Catalytic Converter do exactly?

As your car uses gasoline the exhaust is passed through the converter that is attached to the tailpipe after the exhaust manifold but before the muffler.  As the gas passes through the converter and the ceramic honeycomb or beads that are coated with a catalyst of a mixture of platinum, palladium, and/or rhodium, the carbon monoxide is converted into carbon dioxide, excess hydrocarbons (most likely excess gasoline) is converted into carbon dioxide and water, and Nitrogen Oxide is broken into Nitrogen and Oxygen.

Okay, I know what it does, why do they get stolen so often? 

For the same reason that stereos and air bags are stolen, they are light weight and bring in money.  There are repair shops that purchase stolen parts to get jobs done, or sold to scrap metal dealers who in turn sell the components to recycling companies that can melt down the metals and separate them for sale.  There was a peaking of catalytic converter thefts in 2008 when Platinum was at 2000USD per ounce, Palladium was at 445USD, and Rhodium was at 7300USD.

But I was told that I should take the catalytic convert off my car.

Okay here we go again, cars are engineered from the ground up.  This isn't like the original catalytic converters in the 70s that were put on engines that were designed in the 50s or 60s so with those vehicles performance was affected.  Removing converters from today's vehicles will reduce performance much like adding them affected performance in the 70s.