Yep well at least to shut the rattle up. It maybe still working okay. Problem is on the V8's the downpipes are all one piece. So your be doing both sides anyway. Also as it's one piece you will need to drop the gearbox cross member and I hope none of manifold studs snap. The drivers side manifold is a right arse to remove if it needs to come off to be drilled and tapped.
 
Thanks - so new down-pipe assembly required then?
Nope, drill a couple of small pilot holes in the casing either side, then screw in a couple of lengthy self-tappers until you feel resistance, that'll stop 'em rattling. Screwing cats will normally get you locked up - but not in this instance.
 

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