Why does the engine light turn yellow right after filling up a full tank of gas?

[DelMiguel]

The reasons why the engine light turns yellow right after filling up a full tank of gas are as follows: 1. Poor fuel quality: Gasoline is particularly important for cars because without gasoline, the car cannot start. The quality of gasoline is equally important for cars. Poor fuel quality can lead to insufficient engine combustion, causing the engine light to turn yellow. 2. Poor engine combustion state: When designing cars, to ensure the engine is in good working condition and to maintain its normal working lifespan, an oxygen sensor is specifically installed for the engine, mainly used to monitor the engine's combustion state. Once the engine's combustion state is poor, the yellow light will turn on. 3. Issues with the fuel supply system: The fuel supply system includes many important small components, such as the fuel tank, fuel pump, fuel pressure regulator, etc. When these components have problems, it can lead to issues with the fuel supply system. Although the car can still drive, the engine light will turn yellow.