I just replaced the O2 sensor to fix something else, didn't seem to have any effect on idle. It has been doing this since I replaced the fuel pump. I should clarify, the idle isn't terribly rough, but it sounds kinda like it has a lumpy cam in it. I've poured half a can of seafoam through the throttle body, never cleaned it properly tho. Some times when it's warm I have to give it throttle to open up the throttle body and get it some air.