If you do decide to decat the header, you can purchase a oem decatted header from the auction site pretty reasonable price. This way you can keep your header for just in case. Others may know more than I, but the ox sensors are before the cat and if your state does not have epa test for motorcycles, no issues there. Also, a Harley tech would have to have a reason to look under the bike to see a different weld on the exhaust pipe. Not sure if when a tech access the ecm, it has the ability to detect exhaust flow, etc. Yes, a tune would be good to do and a Harley tune keeps your warranty, but not the best tune out there.
I did all the above, HD tune, stage 1 and street cannons, it worked for me and I have not had any issues with the Harley dealer.
Like I mentioned, other will know more than I.
2018 FLTRXS, Vivid Black, KW Slicer Front Fender, Sundowner Seat/Modified by Mean City Cycle
Last edited by FLTRXS18; 05-24-2019 at 06:57 PM.