What Causes the Malfunction Light to Illuminate and Lack of Power When Accelerating?
3 Answers
The reasons for the malfunction light illuminating and lack of power when accelerating may include a faulty oxygen sensor or substandard fuel quality. When the engine malfunction light comes on, it indicates that the engine parameters have changed, with poor fuel combustion being the primary cause of these parameter variations. The engine malfunction signal is issued by the ECU, which controls all electronic components of the engine, such as the electronic throttle, fuel injectors, fuel pump, etc., covering various systems including intake, fuel, and ignition. After the engine malfunction light illuminates, it is essential to safely pull the vehicle over to the roadside, turn on the hazard warning lights, place a warning triangle 100 to 150 meters behind the vehicle, and contact a relevant repair shop or 4S store.
Last week my car had the same issue - the check engine light came on while driving, and it felt like the car was struggling to climb a hill when accelerating, with no power at all. Having driven for over 20 years, I've encountered this several times. Usually it's a faulty sensor in the engine, like a bad oxygen sensor or mass airflow meter, causing the ECU to miscalculate fuel supply. It could also be ignition coil failure or bad spark plugs leading to incomplete combustion. In my case, it was caused by insufficient fuel pump pressure - when gasoline can't be delivered properly, the car naturally loses power. Don't underestimate this problem - sudden deceleration while driving can be dangerous, especially on highways where rear-end collisions may occur. I immediately drove to the repair shop and replacing the faulty part fixed it. Regular checks of engine oil and air filters can help prevent similar issues.
Speaking of the malfunction indicator light coming on and lack of power during acceleration, as someone who frequently works with modified cars, my experience suggests it's often an electronic system issue. When the engine control unit detects faulty sensor signals—like problems with the throttle position sensor or fuel pressure sensor—the light will illuminate. Simultaneously, if fuel injection control fails and fuel supply decreases, the car loses power. A clogged catalytic converter can also cause this, as restricted exhaust flow affects performance. I recommend first reading the trouble codes; an OBD scanner can help pinpoint which circuit is malfunctioning. Avoid highway driving in this condition—it will drastically increase fuel consumption and potentially damage the engine. Have a reliable technician inspect it, starting with simple fixes like replacing spark plugs or filters.
