Regal cars can't be high-profile when they are idle.

The common situation of high idle speed is 1: just after cleaning the throttle, the computer needs time to adapt to the change of throttle opening, so the idle speed is high. 2. Just starting the car, the water temperature is low, the engine is controlled in open loop, and the idle speed is high. When the water temperature rises, the engine is closed-loop controlled, and the correction signal is used to idle and stop. It's normal to leave at around 3:900. These are all high-speed idle cars. If the idling jitter is unstable, you should go to a repair shop for inspection. If the idle speed is too high, check the idle speed signal and air intake signal.