yup...some time ago. So, is that must be adjusted again?
i think throttle body vacuum hose was leak...
I checked the vacuum hoses but no leaking/cracking. Normally, if vacuum hoses leak...the vacum will drop and make the engine RPM unstable.

I checked the vacuum hoses but no leaking/cracking. Normally, if vacuum hoses leak...the vacum will drop and make the engine RPM unstable.