I had a slight rattle at startup coming directly from the rear motor/under the front of tunnel the last trips so I got down for a exhaust donut replace now in the offseason. Read the great diy donut thread here on TY for the procedure and got into it, was a strait forward job and not a single bolt was stuck, rusted or stripped actually. (Well that NEVER happen, so just that alone is worth a beer!! ) Thing is that the donuts looked just fine apart from a single v-clamp that had spun itself and lost just a little tension, so i just grinded the clamps a few millimeters and put them on withe the old donuts. From what i have read the donuts do fail often, do they just split into thousand peieces and blow out or do they shrink and leak?