What is the reason why the car still hisses after the flameout?

You want to know, "What's the reason for the car's sizzling after the flameout?" The relevant contents are as follows:

The reasons for the hissing sound after the car is turned off are: 1, and the cooling sound of the three-way catalyst: the normal working temperature of the three-way catalyst is 400 to 800 degrees Celsius. After the car is turned off, its work will stop slowly, the temperature will drop, the metal parts inside will expand with heat and contract with cold, and then make an abnormal noise; 2. Under normal circumstances, the exhaust gas temperature reaches 700 degrees Celsius, which accelerates the temperature generated by the rapid rotation of the turbine, and after the flameout, it expands with heat and contracts with cold to make an abnormal sound; 3. Abnormal noise caused by uneven cooling of the engine: After the car runs for a period of time, the engine temperature is very high, and the temperature of all parts decreases after the flameout, which will lead to abnormal noise caused by friction of metal parts inside the engine due to cooling contraction.