After reading the stringent EPA crap that the SEPST is required to adhere to is it worth even purchasing? I would be applying it to a 2018 Fat Bob 114 with no other changes other than S&S Grand National slip-ons. The only thing I am getting that tells me I'm lean is the occasional pop when shifting. I have zero decel pop. It does seem a bit toasty at lights when it's above 80° or so but my left leg wants to hit the primary and my right leg wants to hit the rear head. New bike so I'm a bit concerned about warranty. I used a FP3 on a past bike with good results but that will nullify the warranty. I'm truly at a crossroads here. Is the SEPST even worth the cost????

 

IMO, I wouldn't bother with the SEPST because, as you say, it has to meet EPA standards. You're OK as is with just a muffler change. The pop on upshift is actually a rich condition at shift points.
If you go with a tuner later on, stick with the FP3. Auto tune works quite well with it.

 

After posting this thread I have since found out that the bike is running the SEPST canned tune and I now have the tuner and cables. I am going to run at least one auto tune run over the weekend so see if that makes any difference.

 

Anyone know the procedure of removing the canned SEPST tune and reverting back to the stock tune? I've not been happy with the results of the SEPST and have ordered up a Fuel Moto PV2 and evidently the bike needs to be running the stock tune before flashing it with the PV2.