I just talked to my mechanic and he thinks the idle valve could be dirty. He said those things get gunked up and cause those kind of symptoms. It doesnt do it while actually moving, it only happens when slowing down and stopped.

As for my battery, it's a 60 month Interstate (the best battery ever!) that's about 18 months old. It starts up fine when cold, except when I shut the car off when the idle is rough like Ive been talking about. Last night it took a few minutes to get the thing going, but it did eventually start.

Hopefully its just the valve and also hopefully it can just be cleaned and not replaced. Could a dirty fuel filter cause these symptoms?