A friend noticed on my 999r that the race kit is one link pipe with back box, the link link pipe has no catalyst and replaces the standard one which does have one.
He asked that why isnt there one on each pipe.
Now that sounds like a good question!
Its got me wondering, but surely wont this upset things like the gas back pressure balance and a whole load of other things etc if there is a catalyst on just one pipe(cylinder)
anyone know or got an answer?