What is the reason why the noise inside the car becomes louder after washing the throttle?

In this case, the vehicle will naturally get better after driving for a period of time. After the vehicle cleans the intake valve. Because the flap on the throttle still moves in the original way, the flap is not in place, but all kinds of carbon deposits have been cleaned up, so the air intake will be more than normal. Therefore, the idle speed will increase slightly and the sound inside the car will be louder.