What Causes the Emission System Fault Light to Illuminate?

[CadenFitz]

The reasons for the emission system fault light to illuminate include: 1. Poor fuel combustion state, where fuel is not burned or burns incompletely, causing engine knock and excessively high internal engine temperatures; 2. Poor fuel quality, leading to unclean engine cylinders and accumulated carbon deposits; 3. Faults in the oxygen sensor itself or its wiring, or faults in the sensor control unit. If this fault light comes on while driving, it indicates that the engine parameters will change, and the engine may lack power or shake severely. In such cases, it is necessary to visit a nearby repair service station for engine inspection and maintenance. If this issue is not resolved promptly, the engine combustion state will not return to normal.