Hi all. After hearing an 883 with some nice Python slip on mufflers I'm considering getting a set for my Forty-Eight.

http://www.pythonperformance.com/pro...oductId=220068

Currently, I have the stock catalyst mufflers installed (Harley part number 64900212). If I'm only changing the mufflers and nothing else, will a retune be absolutely necessary?

 

No... a retune will not be necessary. You may experience 1 or 2 pops on hard decal but probably not with just muffler slip-ons.


I ran V&H slash tip slip ons and experienced a few pops. Once I added the high flow AC, the popping was a lot more prevalent.


At that point I decided to re-tune. (Fuel Pak III)

 

Not necessary.

 

Nope, not necessary. The ECM will adjust for the difference in the slip-ons, and you should be at the same AFR you are at currently.

If it is a stock tune (or HD download), you will still be EPA lean. You might be surprised how much better your bike will run with some help from a Tuner....whether you keep your stock slip-ons, or go with some aftermarkets.

 

As those have mentioned above, it is not "absolutely necessary" but IMHO it is always a good idea to re-tune when you change your air flow....your engine will run cooler and you will get the most out of your mods.

 

I tried to do teh slipons only. Got tired of the crazy popping at decel within a week and got a tuner/air cleaner.