What is the main function of a Three Way Catalyst (TWC)?

The main function of a Three Way Catalyst (TWC) is to reduce harmful emissions from the exhaust gases of internal combustion engines, specifically focusing on carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The TWC facilitates chemical reactions that convert these pollutants into less harmful substances.

When the exhaust gases pass through the catalyst, it promotes reactions that convert carbon monoxide into carbon dioxide, hydrocarbons into carbon dioxide and water, and nitrogen oxides into nitrogen and oxygen. This capability to address three major types of emissions—hence the term "three way"—is critical for meeting stringent emission regulations and improving air quality.

While measuring engine temperature and timing, increasing fuel efficiency, or converting specific gases into others may contribute to overall vehicle performance or emissions reduction, they do not capture the primary role of the TWC, which is specifically designed for emissions control.