Arrow full system exhaust

[zirconxi_imp]

Mine changed both full system exhaust and k&N air filter (mostly for sound tune and aesthetic), but still retained stock ECU. Not sure if anything had gone wrong but she seems to run fine. Power wise, according to my butt-o-meter, not much change on the bottom rev, but high rev slightly easier to reach. If I am right, if stock bike come with an O2 sensors, fitting after market exhaust without one will require additional mod else the check engine light will light up.