M8 performance upgrade

[happyman]

Harley stepped up and agreed to comply with the new Euro 4 Emission standards for all it '17 bikes. Only product manufactured by HD and approved to these standards will keep the warranty. Any mods to ignitions, or exhausts that do not comply VOID the warranty.
A modified exhaust (removal of the cat) will certainly require changes far beyond anything allowed under warranty. Same rule would apply to any Ecm other than approved HD with their downloads.
FWIW, I would do the Stage 1 (if you can't live with stock),ride out the warranty, then modify to your hearts content. The other choice to ignore warranty and modify now, never expecting HD to cover any part of the powertrain. Buffalo

if a person has  a 17  CVO and just installs a set of the  SE muffs,  that does not require the tuner, correct?  then if you  install  the  high flow  A/C, with the muffs  I take it you need to install the tuner and proper map?  have never seen in the book where it says to tune with just the muffs but may have missed it.   
Thanks

[twincamzz]

2017 P&A catalog ( page 501) says "All models require ECM calibration with Screamin' Eagle Pro Street Tuner for proper installation " however nothing about retune is mentioned in installation instructions for the Street Cannon slip on mufflers. FWIW, my dealer installed a set of these on my 2017 Limited Low back in August w/o  a retune & motorcycle is running great 6200+ miles later.

http://www.harley-davidson.com/store/street-cannon-performance-slip-on-mufflers-pa-18-64900552--1

https://serviceinfo.harley-davidson.com/sip/service/document/61691

[Admiral Akbar]

I'm wondering why car engineering has evolved to the point where they are making huge hp with high flow after market cats when doing extensive mods, why aren't bike exhaust manufacturers able to do the same?  A 'friend' removed his cat by ramming a big honkin screw driver into it and then sucking out the pieces and then realizing it was magnetic (?) pulled out all the resulting debris with one of those extendable mags ya use for retrieving nuts etc. Afterwards it's clean and clear inside and is still stock on the outside😈

Size.

[1FSTRK]

2017 P&A catalog ( page 501) says "All models require ECM calibration with Screamin' Eagle Pro Street Tuner for proper installation " however nothing about retune is mentioned in installation instructions for the Street Cannon slip on mufflers. FWIW, my dealer installed a set of these on my 2017 Limited Low back in August w/o  a retune & motorcycle is running great 6200+ miles later.

http://www.harley-davidson.com/store/street-cannon-performance-slip-on-mufflers-pa-18-64900552--1

https://serviceinfo.harley-davidson.com/sip/service/document/61691

In your first link when you click on the features tab it specifies

Requires ECM calibration              (YES)

[happyman]

2017 P&A catalog ( page 501) says "All models require ECM calibration with Screamin' Eagle Pro Street Tuner for proper installation " however nothing about retune is mentioned in installation instructions for the Street Cannon slip on mufflers. FWIW, my dealer installed a set of these on my 2017 Limited Low back in August w/o  a retune & motorcycle is running great 6200+ miles later.

http://www.harley-davidson.com/store/street-cannon-performance-slip-on-mufflers-pa-18-64900552--1

https://serviceinfo.harley-davidson.com/sip/service/document/61691

In your first link when you click on the features tab it specifies

Requires ECM calibration              (YES)

if you just do the muffs its not really a stage 1?  the  High flow  A/C that are available would make it a stage 1?