What is the cause of Ford Focus engine fault light?

The reasons for the failure light of Ford Focus engine are: 1, and the exhaust emission is not up to standard, such as poor fuel, failure of three-way catalyst, excessive carbon deposition in intake pipe, blocked fuel nozzle, oxygen sensor failure, and occasional engine fire. , will lead to engine failure lights. Replace the three-way catalyst; 2. The fault light is lit due to poor engine system, such as the fault of accelerator pedal sensor, throttle position sensor, air flow meter and crankshaft position sensor or poor line contact, which will lead to the lighting of engine fault light; Carry out maintenance and replacement according to relevant maintenance methods; 3. Some vehicle gearbox system failures are also indicated by engine failure lights, such as internal gearbox failure, slipping, high temperature, etc. Need to go to the repair shop for maintenance inspection.