Idle problems.

[D-Train]

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.