Lexus es240 changed the spark plug after washing the accelerator. What is the high idle speed?

Lexus es240 has been idling at high speed after cleaning the throttle and replacing the spark plug. What happened? When the vehicle speed drops to the lowest level, it means that during the deceleration process, 5-4 4-3 3-2 does not shake, and only reaches the lowest gear. This is not a gearbox design problem. If there is a forced downshift design, that kind of car 4-3 3-2 will shake and vibrate. You only have the lowest speed and minimum fuel injection. . . Considering that it is a new car, it is very important to check the oil circuit, and the impurities in the oil circuit will affect the combustion jitter. . New car, how can there be a lot of impurities? This has nothing to do with the new car. Even if a large gas station cleans the underground oil tank, no one can guarantee that the oil impurities added each time will not exceed the standard. Different from EFI, direct injection engine is very sensitive to fuel combustion, and high compression ratio is also an important factor for sensitive fuel. . . So I suggest you clean the oil tank with Siyoupu cleaning agent. Generally, it will be clean after running 500 kilometers, and the new car will be fine. Combustion will not shake after cleaning,,, Do not add high-grade fuel. Advanced fuel can only cover up the problem of poor combustion and cause more harm.