06 2.2 idle speed adjustment

i have a question about the possibility of adjusting the idle speed? when i driving the x-way for the most part and i have to stop the car i have noticed the idle speed to be 500 or lower and the engine start to stumble. is there a way to correct this by increasing the speed? the car has 122k on it so maybe something is worn to cause this that i can correct if i can find it? thanks

Idle RPM is a function of the PCM controlling the IAC for the programmed target idle. If the IAC is sluggish, clogged, or the TB has heavy deposits the system may not be able to achieve proper idle control.

It may be helpful to throttle body, throttle plate and IAC air passages. If there is no improvement remove the IAC itself for cleaning and lubrication.