BMW 328is check engine light on despite good performance after topping off oil on BMW 328is

Some BMW 328i owners report experiencing a persistent check engine light even when the vehicle performs well after topping off the oil. This issue may arise from sensor problems, such as a faulty oxygen sensor or malfunctioning mass airflow sensor, which can trigger the light regardless of the car's performance. Additionally, emissions control system faults may cause the check engine light to stay illuminated despite the vehicle running fine. Some owners find that the light remains on due to an incomplete reset of the system after oil top-up, highlighting the importance of properly clearing diagnostic trouble codes. Furthermore, underlying engine issues, like a clogged air filter or valvetronic problems, could also contribute to the persistent warning light. It is recommended that owners have their BMW 328i inspected by a qualified mechanic to diagnose the specific cause, as neglecting the check engine light could lead to more serious problems in the future.