Which component works to reduce harmful emissions in a vehicle?

The catalytic converter is a critical component in reducing harmful emissions from a vehicle's exhaust system. It facilitates chemical reactions that convert toxic gases such as carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful substances, primarily carbon dioxide and nitrogen. This process not only helps in complying with environmental regulations but also improves the overall air quality.

The oil filter, while essential for maintaining engine oil cleanliness and prolonging engine life, does not directly deal with emissions. The fuel injector is responsible for delivering the correct amount of fuel into the combustion chamber but does not have a function related to processing exhaust gases. Similarly, the air filter protects the engine by filtering out dirt and debris from the air entering the combustion chamber, but it does not have a role in reducing emissions. Thus, the catalytic converter stands out as the primary component responsible for managing and reducing harmful emissions in a vehicle.