There is a fault code 0 157+00 on Omar truck. What's with the yellow engine trouble light?

The engine fault light turns yellow for the following reasons:

1. The throttle is too stolen, resulting in too rich mixture.

2. Excessive carbon deposition in the engine leads to unqualified exhaust emission. The reason why the carbon deposit exceeds the standard may be that the quality of the frequently used engine oil is not very good, and it is not maintained on time, or it is also related to the usual driving habits.

3. The fault of the engine oxygen sensor will also cause the engine fault light to light up.