A Honda Odyssey saloon car with a mileage of about 85 thousand km is equipped with the K24A6 engine in 2008. The engine of the car is shaking and accompanied by malfunction of acceleration. Fault diagnosis: 1) use HDS to read the engine fault code without any fault code display. 2) remove the intake hose and check the throttle body to find serious internal coking. 3) remove the spark plug and find that there are colloidal substances in the spark plugs of the two cylinders, which indicates that the gasoline quality is not good enough. 4) ask the car owner, know that the car has been in the same gas station, and the last time is added gasoline in other gas stations, only after the above failure, it is concluded that the gasoline quality is not good caused by engine failure, the owner of the oil road, circuit cleaning. 5) remove the throttle body and the injector. 6) use the carburetor cleaner to clean the throttle body and put the fuel injector on the ultrasonic cleaner. After cleaning, restore and clean the oil circuit with the dismantling cleaner. 7) use HDS to match the engine idle speed, start the vehicle, the engine idle speed is stable and accelerate normal, troubleshooting. Maintenance summary: it is suggested that the owner use good quality gasoline, because the electronic control engine requires high quality of gasoline, and the use of the fuel with no passing quality causes incomplete combustion, causing engine carbon accumulation, and eventually lead to abnormal engine work.