I don't even have the bike yet (2018 Monster 821) and I already looking to get rid of the f-ugly exhaust that comes with the 2018 Monster 821. I guess it's so big and ugly because they incorporated the catalytic converter or the anti pollution crap into the structure of the exhaust down stream as compared with the ugly bladder cat that cam with my S4R.

Anyways I gotta replace them and I kinda like the MIVV or the Termignoni for both style and sound. Then I'm wondering if the ECU is gonna have to be remapped as well. any thing else I will have to do after the exhaust is changed? Airbox etc?