What might be the reason for the check engine light illuminating in my 2013 Subaru Impreza?

If the warning light comes on in your 2013 Subaru Impreza, the first step is to inspect the gas cap. A loose or damaged cap can cause fumes to leak, leading to the light turning on. Another common issue is a malfunctioning oxygen sensor, which monitors oxygen levels in the exhaust system. This data is used by the car's computer to adjust the air/fuel mixture going into the engine cylinders. A faulty oxygen sensor can impact the performance of spark plugs and the catalytic converter. Additionally, a problematic mass airflow sensor could be a culprit. If the check engine light is accompanied by difficulties starting the car, rough idling, or changes in the throttle pedal response, the mass airflow sensor may be to blame. Other possible reasons for the light turning on include problems with spark plugs, spark plug wires, ignition coils, catalytic converter, vacuum system, hoses, aftermarket alarm system, or exhaust gas recirculation valve.