Hi ,JRJ,The tapered silencer protrudes a little more than stock and looks great.The fitting is easy but follow cosmic debrilis thread under mods. for the removal of stock system.he mentions not being ableto find the plug and socket on the lambda wire, well the Pand S are easy to see if you remove the bright trim.I suggest you screw in the lambda into the new pipe before fitting to the bike..Louder than the stock but not annoying ,you will love blipping the throttle.I don't know about retro fit of a cat.,why would you want it?As I said the system is great quality and finish.Any further questions just shout up.Brianj.