Which system is responsible for controlling the exhaust emissions of a vehicle?

The exhaust system is responsible for controlling the exhaust emissions of a vehicle. This system plays a critical role in directing harmful combustion gases away from the engine and the passenger compartment while also reducing pollutants before they are released into the atmosphere. Key components of the exhaust system, such as the catalytic converter, are designed to convert toxic emissions—such as carbon monoxide and hydrocarbons—into less harmful substances like carbon dioxide and nitrogen. By ensuring that these emissions are effectively managed, the exhaust system helps vehicles meet regulatory standards for air quality.

The intake manifold system primarily focuses on directing the air-fuel mixture into the engine and does not have a direct role in managing exhaust emissions. The fuel injection system is responsible for delivering the correct amount of fuel to the engine for combustion, which influences emissions but does not directly control or treat exhaust emissions. The cooling system manages the engine temperature to prevent overheating and does not interact with exhaust gases or emissions control. Therefore, the exhaust system is the correct answer as it encompasses the necessary components specifically designed for emission control.