How to solve the abnormal noise of Volkswagen Bora exhaust pipe?

The abnormal noise of Bora exhaust pipe may be due to the unstable idle speed of the vehicle. There are many reasons for the unstable idle speed of vehicles. When the idle speed is unstable, the sound of natural exhaust pipe is different from usual. According to different models and designs, there are many reasons: air intake: a. Leakage or blockage of the air intake system can lead to. B. Idle speed control part: stepper motor and throttle body are dirty or leaking. C sensors such as air pressure, temperature and throttle position are abnormal, and the data is incorrect. Oil pipeline: A, blocked, unobstructed, etc. Will lead to. B. The electric fuel pump is abnormal or the fuel filter is blocked or blocked for various reasons; C. Abnormal choke: It can be due to its own quality failure, or it can be due to various defects such as foreign body blockage, poor sealing and rubber ring aging. Abnormal rail pressure.