What are the reasons for the OBD light being on and the vehicle lacking power in a diesel car?

[FelicityFitz]

When the OBD light is on in a diesel car, it indicates that the vehicle's emissions exceed the standard or there is an engine malfunction. Below are the relevant details: Introduction: If a fault occurs, consider replacing the carbon dioxide sensor and cleaning the three-way catalytic converter. Additionally, repair the three-way catalytic converter. Extended Information: When the vehicle starts and performs a self-check, the engine malfunction indicator light will illuminate. If the engine malfunction indicator light stays on, it suggests there may be a mechanical issue with the engine. There are many reasons why this fault light stays on, and it is generally difficult to diagnose and resolve on your own. It is best to stop the vehicle and, if necessary, take it to a 4S shop for inspection and repair. When the vehicle starts and performs a self-check, the coolant temperature indicator light will illuminate, showing two possible colors: a blue light indicates the coolant temperature is too low, while a red light indicates the coolant temperature is too high.