Road Glide banner

2010 FLTRX: Anyone have D&D 2-1 Fat Cat system

8578 Views 25 Replies 11 Participants Last post by  dklanecky
I have been looking at the D&D exhaust. Wondering if anyone has the 2-1 Fat Cat or even the Boss slip on. The website has the dyno info on the Fat Cat but not the slip on with the OEM head pipe. It also says no tuner needed.
21 - 26 of 26 Posts
I put my Fat Cat 2:1 on Friday night. I had an HD stage 1 with a K&N filter off of my '08 RK that I used for now. I am planning on putting the Performance Maching Stage 1 on soon. The sound is great and I couldn't be happier. I will get some pictures posted as soon as I can.
Here is a photo of the D&D Fat Cat 2:1 with slant cut. They look and sound great!


See less See more
I have the fat cat D&D 2 INTO 1 full system with a hi flow breather on my 2010 Road Glide Custom. The guy at D&D told me it was plug and play, no tuner necessary. Every dealership I spoke with said that was not going to work and I would have to dyno and tune the bike to get the performance or it would run lean. I started recording my oil temp and ordered the full D&D exhaust. My local dealer installed it with the hi flow breather and against their wishes did nothing else. The bike runs significantly stronger, is not running any hotter and sounds great. I now have about two thousand miles on that exhaust and really feel great about my decision.
Congrats on the new pipes. I read D&D's stance on ECM programming with skepticism too. Basic engine principals dictate that more air flow requires more fuel. Physics, pure and simple. I can see their claim being valid if you don't change the breather, but I'm convinced you're running lean. I know I was with the Arlen Ness Big Sucker and D&D combo. Just the ride to my dyno tuner was very lean. HDs are already lean from the factory to appease the EPA. I'd keep a close eye on the temperature and look at the spark plugs now and then. It would be a bummer to have a warranty invalidation issue because of a known condition.
How much temperature difference would there be if running lean? So far I haven't seen mare than 240. However, we haven't had much real hot weather yet. So far though I am very happy. I also notice virtually no difference in my MPG
Read the plugs......

You really need to pull your spark plugs and check them out. They are likely indicating the bike is running very lean.......There are many sources of this info, but here's one to get you started.
21 - 26 of 26 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.