Incorrect replacement of air flow sensor. The service technicians are reminded to note when ordering and replacing the air flow sensor that the air flow sensors used in Shanghai Santana 2000 and 3000 cars are different and cannot be used interchangeably. Part number of the air flow sensor used by Santana 2000 is 06A 906 461, without internal temperature sensor; Santana 3000 with AJR or AYJ engine (meeting Euro III emission standard), adopting throttle with the same mechanical structure as Santana 2000, The part number of the air flow sensor used is 06A 906 461; Santana 3000 equipped with a BKT or BKU engine (meeting Euro III emission standard), electronic throttle, part number of the air flow sensor used is IJD 906 461, internal With a temperature sensor, its characteristics are completely different from 06A 906 461.
If the air flow sensor is installed incorrectly, it means that the engine cannot get the correct amount of fuel. In the mixed-air open-loop control phase, the three-way catalytic converter may be overheated and burned or the engine oil consumed too high. During the closed-loop control of the air-fuel mixture, the deviation may be corrected by the oxygen sensor signal, resulting in the air-fuel ratio control amount. Larger, unstable system operation.
Solution: Replace the correct air flow sensor.
Special reminder: Vehicles that meet Euro III emission standards can be identified by the following markings: E3 or LPG on the upper cover of the engine, and BKT or BKU on the nameplate of the engine on the nameplate of the vehicle.