Engine Misfire & High Idle Speed

Hello,

After searching extensively but not finding what I need, I unfortunately have to post my problem here.

My 1Z is running really well, but:

The idle speed is usually slightly elevated, sometimes up to around 1100 RPM, and very, very rarely it's close to the correct value. This is regardless of whether the engine is warm or cold.

And there's a noticeable jerkiness during acceleration (both with the pedal and using GRA) below 2000 RPM.

When I shift into neutral while driving, the engine sputters for a few seconds and then suddenly runs smoothly at its (increased) idle speed.

And it slows down relatively slowly from a high RPM, and the speedometer needle sometimes jitters.

I don't know how else to describe it.
If anyone has a tip, I would be grateful.
Good night.

Is the fault memory clear? Are the temperature sensor readings from the engine control unit within a reasonable range?

The error memory is clear, and the temperature sensor seems to be reading correctly according to my VAG-COM diagnosis, however, the temperature gauge in the instrument cluster is not rising properly.