Toyota corolla e120 1.4 vvti 2004

Hi lads I have a problem with my car

When the car is at idle its shunting when I turn the lights on the shunting goes away the idle is not going up and down its staying as is

The work I done so far

I replace the air flow metre
Spark plugs
Check the coils are all working fine
Clean the throttle body and the parts inside the throttle body

Checked intake manifold with brake degrees stays the same

Check for exhaust leaks it's all fine

Other than that the car is running very well when I drive it no issues at all

Plz help