The engine sound of Lexus hybrid car is very loud, and it is accompanied by vibration when there is a serious traffic jam. What is the reason?

The engine sound of Lexus hybrid car is very loud, and it is accompanied by vibration when there is a serious traffic jam.

Too dirty throttle or too much carbon deposit in fuel injector, gear start vibration, cold start and insufficient three-way catalytic temperature are the most common reasons for automobile vibration, because gasoline adsorbed on carbon deposit after landing is sucked into the cylinder by the engine for combustion, and the combustible mixture of the engine is sometimes rare and thick, which leads to idling vibration after cold start. Solution: The company cleans the oil circuit, and checks whether the idle motor has carbon deposit, so it should be cleaned.