What does it mean when the vehicle's engine light is on?

[Boromir]

The reasons for the vehicle's engine light being on are: 1. Sensor damage, poor contact, or signal interruption; 2. Poor engine maintenance; 3. Poor quality fuel and engine oil; 4. Incomplete combustion of the air-fuel mixture; 5. Faulty spark plugs or ignition coils; 6. Fuel pump failure or clogged fuel lines; 7. Clogged air filter. The solutions for the vehicle's engine light being on are: 1. Use fuel additives to clean the entire fuel system; 2. After cleaning the engine, use higher-grade gasoline; 3. Use high-quality fuel additives to improve the cleanliness level of the fuel; 4. Replace the catalytic converter.