Is it necessary to clean the inside of the engine?

Cleaning the air intake system is generally about 20,000-30,000 kilometers. If the air intake is not smooth, it will lead to high fuel consumption, blocked nozzle, unstable idle speed of the car and long-term stuck gas valve. The best way is to check the air filter element frequently or replace it directly, because the carbon deposit in the air intake system is formed by the interaction of impurities in the air and the humidity of the air intake, and regular cleaning is essential. I don't know that long-term problems will cost a lot of money.