How often does Accord 2.0 clean the throttle?

In fact, it can be washed in 30 thousand kilometers. No matter what the air quality is, the throttle should be dirty. If you go to 4S to wash the car, you can say that the car is idling. Let me check. He said that if the throttle is dirty, he will wash it for you for free. If you go to maintenance and say that you want to clean the throttle, you have to pay. If you take it apart, it is estimated that it will cost four or five hundred yuan. Not every 4 S is like this.