How much throttle opening represents cleanliness.

It has nothing to do with the opening. If the throttle is dirty, it will be cleaned if you don't go back. Generally, if the throttle opening exceeds 4%, it should be cleaned. The result of not cleaning is: 1. Failure to clean the throttle for a long time will lead to the wrong throttle opening; 2. At the same time, impurity air enters the engine combustion chamber, and both results will lead to abnormal engine operation; 3. The main reason is that the idle speed is unstable, and the feeling of closing the throttle suddenly appears during driving, and the power drops. In serious cases, it will lead to difficulty in starting and increase fuel consumption.