What impact does a blocked air filter have on an engine?

A blocked air filter significantly reduces airflow to the engine. The air filter's primary function is to allow clean air to enter the engine for combustion while filtering out dirt and debris. When it becomes blocked or clogged, the engine cannot receive sufficient air, which disrupts the air-fuel mixture needed for efficient combustion. This reduction in airflow can lead to a variety of issues, including decreased engine performance, increased emissions, and potential engine stalling.

In essence, the proper functioning of the air intake system is vital for maintaining the correct balance of air and fuel, and a blocked air filter directly compromises this balance, leading to overall inefficiency in engine operation.