funnny you ask that. i'veheard people say there is NOTHING you can do to a stock moby exhaust and i kinda believe em. i've been running sans exhuast for the past couple days (here andthere) with no noticeable difference. if that isnt gonna do anything, your leak wont either. get it patched up, i'd say. some jb weld would do the trick if its small enough.