What could cause the check engine light to turn on?

The check engine light is a crucial indicator in a vehicle's dashboard that alerts the driver to potential issues with the engine or its components. One common cause of the check engine light turning on is misfires. When misfiring occurs, it means that one or more cylinders in the engine are not firing as they should. This can lead to unburned fuel entering the exhaust system, which not only affects engine performance and efficiency but can also damage other components, such as the catalytic converter. The engine control unit (ECU) detects these misfires through various sensors, prompting the check engine light to illuminate as a warning to the driver.

While other options may impact overall vehicle performance, they do not directly trigger the check engine light. For instance, improper tire pressure and dirty air filters affect handling and fuel efficiency but are managed separately from the engine diagnostics. Faulty windshield wipers impact visibility and safety rather than engine function directly. Hence, misfires are specifically linked to the engine's performance and are a primary reason for the check engine light activation.