Unstable idle at high RPM

Is anyone experiencing unstable idling with their car? How did you solve it?

Does this car feel unstable at high speeds?

T8 idling at 1000 RPM, what's going on?

Is the engine RPM high when driving at high speeds with the Ousheng 2.0 5-speed?

Have you ever experienced unstable idling? Any solutions to fix it?

Why is my 2018 1.6 manual transmission car having unstable idle when cold started?

When starting a cold car, the RPM goes up to 2000 and then drops to 1500 but doesn't go any lower. The high idle speed is causing high fuel consumption, 20 liters for 300 kilometers! The idle speed is too high, and so is the fuel consumption. Can any experts provide a solution? 🙏

Why is the idle speed around 600 to 700 RPM?

Hey folks, does your Peugeot feel unstable at high speeds?

The Volvo C30 2.0D has a normal idle speed of 850±20 RPM when in gear, but the idle speed is high at 950±20 RPM when in neutral. What's going on?