Like the title says I have a rough stumble when slowing down. It isn't all of the time and happens more often in stop and go traffic, when the engine revs up a tiny bit to move ahead and then revs back down when stopping. The lights also dim when this happens, but only slightly. It does not do this when idling, only when slowing to idle. The PCV system is in functioning order (good suction with glove test) and I'm pretty sure it was replaced by the previous owner shortly before I bought it either way. It has never stalled on me, and is just more of an annoyance, but I'm just wondering the possible cause.