BMW 650i engine light on with unusual smell issue on BMW 650i

Some BMW 650i owners report experiencing issues when the engine light is on accompanied by an unusual smell, which can indicate several potential problems. Commonly, these issues may stem from the gas cap, fuel system, or emissions control system, leading to a gas-like odor. Additionally, a failing catalytic converter can trigger the check engine light and result in strange smells from the exhaust, potentially causing the vehicle to fail emissions tests. Other symptoms that may accompany the check engine light include rough idling, reduced performance, and unusual engine noises. In some cases, minor problems like a loose gas cap can also activate the light without significant underlying issues. Moreover, complications with the Engine Control Module (ECM), such as faulty sensors or software glitches, can necessitate prompt diagnosis and repair to prevent further engine damage. It is recommended that owners have their BMW 650i inspected by a qualified mechanic to effectively diagnose and resolve these concerns.