Present Technology

 

Three-Way Catalytic Converter

The three-way catalytic converter is the standard filter device for all cars manufactured today.  The three-way catalytic converter uses three different processes to reduce harmful car emissions. These three gases are nitrogen oxides, carbon monoxide, and unburned hydrocarbons.  All three are harmful to human health in one way or another.
(Nice&Bryant)

2007 Toyota Prius