07 xb12r exhaust, new zealand

[hospitalfood]

Hi all, starting to think the best thing to do is mod the original exhaust for a bit more sound, can anyone tell me how it is done or who does it in the states please.
I can get local people to do it in New Zealand if I know how it is best done.

Thanks.

Adam.

[hospitalfood]

ok......seems like drummer do this? I like this option because I like the look of the original exhaust. do they do it to the 07 XB12R exhaust???
am I right in thinking the best performance option for me is the drummer with the K&N filter and a re-map of original ecm?
am I right in thinking that the 07 XB12R has an oxygen sensor that detects when its to lean and automatically adjusts the mix???