Stazi was talking about the BOV, but from what I've seen some have a problem Venting, others there is no stumble at all. Crankwalk in these cars is preventable by running a good synthetic oil and not overdoing it on mileage between changes. The 6 bolt block had a different type of oil squiter, the 7 bolt mitsu changed the design of them and they are prone to getting clogged. Once clogged crankwalk slowly occurs, it's more in depth than that but...
Good article about it HERE
http://www.magnusmotorsports.com/crankwalktheory.htmGood luck with it man, I miss my gsx, thing rocked in the snow.