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Dyna Glide ModelsSuper Glide, Super Glide Sport, Super Glide Custom, Dyna Glide Convertible, Super Glide T-Sport, Dyna Glide Police, Dyna Switchback, Low Rider, Street Bob, Fat Bob and Wide Glide.
Removing the cat is always highly recommended in my book.. but to do it you need to literally cut a large rectangular flap into the chamber that houses the converter and then remove it it ain't easy job then you got to weld it all back up..
That's exactly what I did and actually it's a lot deeper and louder sound depending on what type of slip-on you use.. Yes it is louder...
I also found a 2008 head pipe off of Fat Bob that had the 18 mm O2 bungs because I have a power vision and Target tune.. and then I found some Rush slip-ons on eBay and I love the sound I'll get a video of it later post it up I'll reattach it or maybe just post it up depends on what time I can get to it. But it's well worth it because the motor does breathe better but you better get a tuner because with all that more flow you're going to have to change a lot of your ve tables..
Last edited by 98hotrodfatboy; Sep 15, 2025 at 10:17 AM.
I gutted the cat on my 117cu in 2025 Street Glide Ultra recently, did it by removing the right side slip on and drilling/chiseling until the cat material was all out of there, kinda a pain but doable with some patience. I then added DK Thunder torque inserts and tuned the bike, the result was a slightly deeper and slightly louder sound(not an earth shattering difference IMHO). The Thunder torque inserts are most noticeable as they add a little "crack" in the exhaust note and they add a consistent decel sound that is more tuned sounding vs open exhaust. After tuning I feel my bike runs even better than it did prior to removing the cat and it def cooled down the exhaust around my right leg area. You don't actually want "Back pressure", you just want to prevent reversion which is exactly what the Thunder Torque inserts are made to do.DK and others have made some good Youtube videos on what reversion is if you want to look into it further. My recommendation is gut/TT Inserts/Tune.... Ride and enjoy!
I found my bike runs much better with the stock exhaust that has the cats. Took off my Cobra slip-ons and put the stock exhaust back on, cats are in the mufflers on my bike, and just by a seat of the pants feel, my bike runs much better.
I found my bike runs much better with the stock exhaust that has the cats. Took off my Cobra slip-ons and put the stock exhaust back on, cats are in the mufflers on my bike, and just by a seat of the pants feel, my bike runs much better.
Well, if your bike is stock, it will run better because the tune is not supporting the Open Exhaust as compared to the stock mufflers..
Well, if your bike is stock, it will run better because the tune is not supporting the Open Exhaust as compared to the stock mufflers..
You're probably right. I bought the bike with those slip-ons installed already and have no idea what kind of tune it had, if any. All I know is that it made a lot of noise and backfired on decel, so I'm guessing it wasn't tuned at all.
I cut the cat out of my 2008 FatBob, stuck a rebar through the baffles and added XIED 02 sensors and it went well, but wasn't a deep enough rumble so put Loud Pipes on and Dobreck Tuner.
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