Wow, excellent explanations! Thanks guys. I did another couple auto tune runs today and now I still get a minute rumble, but, even less pops. I can produce a pop if I cut throttle completely sometimes. Most of it is gone now though. I'll give the enriching on decel option a shot tomorrow and see if it totally goes away.

I'm still reading and deciphering the PV output tables.

How is the OP doing with his prob? I used to run a Cobra Fi2000 PowrPro on my 07 XL1200N. That helped get rid of nearly 100% of backfires and rumbles on decel. It's lower cost than the Power Vision. I opted for the PV on my FXDWG because I'd like more control.

 

I also have a 2012 Fat Boy Lo like the OP and I just put on the Rush slip-ons with the 1.75" baffles. I got some popping on decel as soon as I rode the bike, but I kind of like it.

I plan on getting the full stage one - exhaust, AC and tuner - in about a year anyway, so I'll just live with it til then. I don't think it's hurting anything, right Ryan?

 

If it's a rumble on decel that's normal. If it sounds like a gun firing, please have a tuner check it out. It most likely isn't hurting anything but that's a sign of an air leak or air/fuel issue. If it drives well but pops when returning the throttle to zero position its probably just the setting for 0% throttle and can be tuned out. Representing the manufacturer I have to suggest you have a certified tuner check it out. Most likely it's fine but if you have any concerns your best bet it to have the local tech make sure.
Ryan