I have a 2010 Street Glide and HATE the stock exhaust sound! Most of the options are $$$ unfriendly, but what about this one? I contacted an exhaust firm and was told that one of their employees had a '10 Sweet Glide that they put a slip-on on, with a disappointing result. THEN, they got a 3/4" drill bit, 1' long, and DRILLED OUT both cats in the head pipes!! They removed the O2 sensors before they drilled so as not to damage them. Guess what??? They got that SWEET Harley sound all of us long for! What are the pros and cons of this? I live in rural NE Texas, so the likelyhood of someone ever smog sniffing my pipe in pretty much zilch!! I've thought about warranty issues, what else am I missing? One thing I WON'T miss is the Singer sewing machine exhaust sound! Thanx for any and all replies, Tracy

 

If you drill it with a 3/4" bit it won't come near getting it all out. The cat is completely encased in the pipe, it's ONE cat in front of where the pipes come together and is probably about 4-5" wide there I would guess. To do this correctly it requires cutting the head pipe in half, removing the cat with a dremmel and wire wheel. Then re-welding it.
I'll try to find the pictures I have seen of this process, You'll see that just two 3/4" holes isn't really "Opening" anything. It MAY sound a little better... I intend to do mine the right way.

 

Thanx Jim, I wish I could see those photos. I wonder how the cutting and welding will affect the integrity of the pipe?

 

Here ya go!

First off, this is what it looks like from the muffler, where you would drill from.



Then you buy the coring drill, which costs probably 40.00 at least and you drill out this part,


With this little core the size of your OPENING in the cat,,,,




Here is what's inside the pipe though,,,,,, so do you see what I mean?

 

i'm confused, did they use a 3/4 hole saw?

 

No, they used a "Coring drill" I'll go where I got those and get the picture of the tool too...

 

Holy $hit! That has to choke the hell out of our bikes! No wonder my bike is so quiet even with slip-ons!

 

That makes me gald I kept my 07 Ultra.

 

I've been running factory header with slip-ons also. It didn't sound to bad but I wanted the bike to breathe a little better so I got new V&H header pipes....OMG it's load now. I'm all for loud pipes but it sounds like a drag bike. All I'm saying is totally eliminating the cat' material may not be the best idea if you want your neighbours to still talk to you.

I was told the "cat" material would eventually melt and/or get clogged up with exhaust deposits (as it has done in other makes of motorcycles) and in time will slowly choke your bike.... This look like a good, and cheap way to get around the problem. I think you will need to get your bike tuned after removal though.. ?

 

Do you need a tune after gutting it?
They say no, you wouldn't need to. (They, being Fullsac performance, and others) It seams the PCM can change enough to keep the bikes fuel air settings correct. Even with a muffler change you don't need to remap. IF you do an air filter, and muffler/pipe. Then a map would be expected I guess.

TEE DEE, I can't imagine it being any louder than all the rest of the 09s and back which don't have a CAT. Have you been around many other Harleys before now? J/K,,, really do you think the reason yours is louder than you think it should be is because you have a 103 stage 4 kit?

Also, the cat material won't just eventually "Melt" Back in the day when there was LEADED gas, and the Government mandated the Catalytic converters and UNLEADED gas with the autos having smaller fillerneck openings. People punched them out, and ran leaded anyway. It melted them yes.
Now after many many miles, could the cat clog from normal usage with carbon? I suppose so.

I DO intend to get rid of mine for sure.