When examining an exhaust system, which component may affect emissions?

The catalytic converter is a critical component of a vehicle's exhaust system that plays a significant role in reducing harmful emissions. Its primary function is to convert the harmful gases produced during combustion, such as carbon monoxide, hydrocarbons, and nitrogen oxides, into less harmful substances like carbon dioxide and nitrogen.

When functioning correctly, the catalytic converter lowers the levels of these pollutants released into the atmosphere, thus complying with environmental regulations. Any issues with the catalytic converter, such as physical damage, clogging, or failure can lead to increased emissions, thereby negatively impacting air quality and contributing to pollution.

While the other components mentioned, like spark plugs, fuel filters, and air filters, play important roles in the overall performance and efficiency of the engine, they do not directly participate in the treatment of exhaust gases. Spark plugs ensure proper combustion, fuel filters maintain fuel quality, and air filters ensure clean air enters the engine, but the catalytic converter is unique in its direct impact on exhaust emissions control.