Idle problems.

G'day guys. New to the forum and thanks for having me. 2008 sub Liberty 2.5i wagon. Stock as a rock.
I'm finding my car is idling really low, sometimes at 300 rpm wether the ac is on or not. It seems to happen most of the time when I am coming to a stop, off the throttle, with the brake on. Especially notice it as soon as I've come to a complete stop. Anyone having this prob or hints as to what it is. Never had a problems in the seven years.
Thanks for any help.
I'm finding my car is idling really low, sometimes at 300 rpm wether the ac is on or not. It seems to happen most of the time when I am coming to a stop, off the throttle, with the brake on. Especially notice it as soon as I've come to a complete stop. Anyone having this prob or hints as to what it is. Never had a problems in the seven years.
Thanks for any help.