I just got an entire exhaust system from a 2007 SE Fatboy as a take off with no miles ($100). The mufflers are etched with EPA stuff, but surprisingly they both say "USA CATALYST" in the etchings. They are part# 65964-07 if that helps any. I was thinking about putting them on my 2007 Fatboy, and then adding a K&N RK3909 Filter and a PCIII later. I don't want loud pipes, and don't really care if I get every ounce of horsepower out of it, I just want a little deeper sound, a little cooler running, a little smoother power curve and a few more ponies would be nice.

I searched the net, and I was surprised to see the SE Bikes have Cats on them, and Harley sells Cat and Non-Cat SE Mufflers for the 49 states. Do the Cat Mufflers add more back pressure than the non-Cat Mufflers? Do youthink there would be any issues with putting Cat Mufflers on an 2007 Fatboy? I don't think I have cats on it now, but I'd have to crawl all over to find the etchingsif they even exist on my mufflers. I figure if a bigger Cube SE Engine didn't have a problem with the Cats, my bike shouldn't either.

Many Thanks!

 

I tried '07 CVO Ultra mufflers on my 95" build '06 Ultra and they killed my torque - too much back pressure. I replaced the CVO catalytic mufflers with SE street legal mufflers (80491-07) and picked up5 HP and 9 ft-lbs of torque. I have also seen dyno charts of '07 bikes with a 103" Stage II kit including the cat mufflers in the kit and the numbers were lower than the same build with some after-market slip-ons like Rush or V&H, etc. My suggestion is to avoid the cat mufflers if you want any performance. They are quiet, however.

 

Great question because I just took delivery of a set of 2006 Street Glide slip ons. Want to use them on my 2005 Electra Glide. I also noticed similar "USA Catalyst" imprint underneath. I thought Oh s...t I just bought a pair of California mufflers (bought them in NY State) so I called the local dealer. The guy at the parts desk (sound young and unsure) looked it up and said all mufflers listed were "catalyst" but I want to be sure before I put them on. My bike is under cover right now and I don't feel like crawling under it in 20 degree weather.

I'm going to continue to ask around but would like to hear what you find out. Thanks