What does it mean when the engine yellow light is on but the car is driving normally?
2 Answers
When the engine yellow light is on but the car is driving normally, it indicates that there is a fault in the engine. The fact that the car can still be driven suggests that the issue is not particularly severe. It might just be a faulty sensor or a false alarm. In such cases, you can continue driving temporarily, but for safety reasons, it is recommended to drive at low to medium speeds and then visit the nearest repair facility for inspection and maintenance. The reasons for the engine fault light turning yellow include: 1. Poor fuel quality: Fuel quality is the primary factor causing the engine fault light to illuminate. The anti-knock property of gasoline is indicated by its octane number—the higher the octane number, the better the anti-knock property. For example, 97-octane gasoline has an octane number of no less than 97. Leaded gasoline can cause lead poisoning in the oxygen sensor, making fuel quality a major reason for insufficient engine combustion, which in turn triggers the engine fault light. 2. Issues with the fuel supply system: The fuel supply system mainly includes the fuel tank, fuel pump, pipelines, fuel filter, carbon canister, carbon canister solenoid valve, fuel pressure regulator, and fuel injectors.
Last time my car also had the engine light (yellow) on, but it drove just fine, which really puzzled me. Turned out it was some carbon buildup in the throttle body causing the sensor to falsely report an emission anomaly. It didn’t affect daily driving, but a quick scan at the repair shop revealed the issue. This is quite common—usually minor emission-related problems like a dirty oxygen sensor or fuel quality issues. Ignoring it might lead to gradually increased fuel consumption and long-term damage to the catalytic converter, which gets expensive to fix. My advice? Don’t wait. Borrow an OBD scanner to check it yourself or take it straight for inspection—small cost now saves big trouble later. After all, this light is more of an early warning than an emergency fault, but delaying could raise the risk of other issues.
