What are the reasons for the Audi exhaust valve not working?

[Tobias]

Audi exhaust valve not working has the following reasons: Exhaust valve damage: The exhaust valve is equivalent to an oil-gas separator. When it works normally, it only sucks exhaust gas without sucking oil. When it is damaged, it loses the oil-gas separation function, sucking in oil while inhaling, causing oil to enter the intake tract and combustion chamber, resulting in oil burning phenomenon and severe blue smoke from the exhaust. Accidental addition of low-purity gasoline: Accidental addition of low-purity gasoline can cause the exhaust valve to fail to control the exhaust gas recirculation volume. Excessive exhaust gas participating in recirculation will affect the ignition and performance of the mixed gas, thereby affecting the engine's power performance. Especially when the engine is idling, at low speed, under small load, or when cold, the recirculated exhaust gas will significantly affect the engine performance.