Which component functions as an actuator in emission control systems?

Which component functions as an actuator in emission control systems?

• A. Fuel Injector
• B. Oxygen Sensor
• C. Mass Air Flow Sensor
• D. Spark Plug

Answer: (A)

An actuator is a device that converts electrical energy into a mechanical action to adjust a system parameter. The fuel injector fits this role because it receives electrical signals from the engine control unit and physically opens to spray a precise amount of fuel into the intake or combustion chamber. This direct control of fuel delivery actively influences the air–fuel mixture and, in turn, emissions. The oxygen sensor and mass air flow sensor are data-gathering sensors, not devices that move parts. The spark plug ignites the air–fuel mixture, which is necessary for combustion but not an actuator that modulates emission-related flow or delivery in the control loop. So the fuel injector is the actuator in emission control systems.

An actuator is a device that converts electrical energy into a mechanical action to adjust a system parameter. The fuel injector fits this role because it receives electrical signals from the engine control unit and physically opens to spray a precise amount of fuel into the intake or combustion chamber. This direct control of fuel delivery actively influences the air–fuel mixture and, in turn, emissions. The oxygen sensor and mass air flow sensor are data-gathering sensors, not devices that move parts. The spark plug ignites the air–fuel mixture, which is necessary for combustion but not an actuator that modulates emission-related flow or delivery in the control loop. So the fuel injector is the actuator in emission control systems.