What causes the yellow engine light in Nissan Sylphy?

[BrandonLee]

1. False alarm: A fault code is reported, but the engine works normally. It may be caused by an operation that temporarily exceeded the computer's control range, resulting in the computer feedback fault code. You can first clear the code and then observe whether the fault code reappears. 2. Minor faults: The engine shows no particularly obvious faults, but through computer detection information and further inspection, certain faults that do not affect normal driving or have minimal impact are discovered. These should be identified and addressed promptly. For example, faults like the intake pressure sensor malfunction. 3. Major faults: Such faults can be felt through visual inspection and driving experience, and they severely affect the engine's normal operation, requiring immediate repair. For instance, obvious lack of engine power, which could likely be due to issues like oxygen sensor failure.