My moms '99 OB has a rough idle while stopped in gear. Diriving it is fine.No CEL. No loss of power at all. Changed: fuel filter, plugs, wires, pcv, air filter- made no difference. Haven't had time to clean iacv. That's the last step before I give up. I also noticed that the idle is worst if you come to a quick stop as opposed to slowly braking over a longer distance. Read through countless threads about cleaning iacv--some said it worked others didn't have luck. Looks to be a 50/50chance of success.