What can contribute to engine performance issues leading to a triggered Check Engine light?

Engine performance issues leading to a triggered Check Engine light can arise from a variety of factors, each of which can have a significant impact on engine efficiency and operation. A dirty air filter restricts airflow into the engine, which can lead to poor combustion and a decrease in engine performance. When the engine doesn’t receive the optimal air-fuel mixture it requires, it can result in incomplete combustion, increased emissions, and potential triggering of the Check Engine light.

Water in the fuel is another serious concern. Water can cause fuel misfires, corrosion in fuel injectors, and other detrimental effects, disrupting the combustion process. Like a dirty air filter, the presence of water can also lead to inefficiencies in engine performance, which may prompt the vehicle's onboard diagnostics to illuminate the Check Engine light.

Therefore, the combination of both a dirty air filter and water in the fuel addresses two distinct but interrelated causes of engine performance issues. This is why selecting both factors as contributors is essential in understanding the potential triggers for the Check Engine light. The other options do not encapsulate the full range of issues affecting the engine that could lead to diagnostic alerts.