BMW 430i Gran Coupe check engine light issue after gas fill-up, likely gas cap replacement needed on BMW 430i Gran Coupe

Some BMW 430i Gran Coupe owners report experiencing the check engine light illuminating shortly after refueling, often linked to issues with the gas cap. A loose or missing gas cap is a common trigger for this warning light, making it essential for owners to ensure it is properly secured. While a loose gas cap may indicate a minor concern, the check engine light could also signify more serious problems, such as an oxygen sensor failure. If the light is flashing, owners should turn off the engine immediately to prevent potential motor damage. Additionally, other factors like a dirty mass airflow sensor or a faulty head gasket can also cause the check engine light to activate. It is important to recognize that this light, known as the Malfunction Indicator Lamp (MIL), may not always pertain directly to engine issues. Therefore, checking the gas cap should be a priority for owners experiencing this warning light after refueling.