Gutting Cats
Thread Starter
4th Gear
Joined: Apr 2010
Posts: 4
Likes: 0
Gutting Cats
Hey all...
I'm broke and have a C5. I'm looking to gut the cats for a bit of a sound increase because the catback I purchased is a bit too quiet for my taste.
How should I go about doing this? I live in Florida so I don't have to worry about emissions.
Please don't advise me not to do it and to buy an off-road xpipe or something because I'll be doing that as soon as I can get some headers.
So just a simple guide will do. Thanks!
P.S. I searched before posting this thread and I couldn't find a how-to or a guide.
I'm broke and have a C5. I'm looking to gut the cats for a bit of a sound increase because the catback I purchased is a bit too quiet for my taste.
How should I go about doing this? I live in Florida so I don't have to worry about emissions.
Please don't advise me not to do it and to buy an off-road xpipe or something because I'll be doing that as soon as I can get some headers.
So just a simple guide will do. Thanks!
P.S. I searched before posting this thread and I couldn't find a how-to or a guide.
Last edited by Vette115; Apr 9, 2010 at 10:27 PM.
Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
Not a simple job on the stock exhaust. It's all a 1 piece unit type of thing. Not like the old days where you'd just disconnect the exhaust pipe at the cat then ram a pipe in to bust up all the innards. You might be able to remove the whole thing then get down to the cats from the front side but I highly doubt it and why even bother? Enjoy what you have until you can buy what you want. If sound is what floats your boat then just do a simple inexpensive bypass mod on the mufflers?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Your going to gain about 5-6 HP and improve the sound quality MINIMALY. 
If you want MAJOR improvements,,,,,,,,rip off the mufflers and run straght pipes and "BAM" ,,,,,,,,,,you get MAX noise!
If you want MAJOR improvements,,,,,,,,rip off the mufflers and run straght pipes and "BAM" ,,,,,,,,,,you get MAX noise!
Thread Starter
4th Gear
Joined: Apr 2010
Posts: 4
Likes: 0
Not a simple job on the stock exhaust. It's all a 1 piece unit type of thing. Not like the old days where you'd just disconnect the exhaust pipe at the cat then ram a pipe in to bust up all the innards. You might be able to remove the whole thing then get down to the cats from the front side but I highly doubt it and why even bother? Enjoy what you have until you can buy what you want. If sound is what floats your boat then just do a simple inexpensive bypass mod on the mufflers?
Are the stock headers and stock midpipe all one piece or do they disconnect? If they disconnect, I'd imagine it being pretty easy to gut the cats.
Tech Contributor
Joined: Jan 2007
Posts: 19,341
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From: Dyer, IN
Thread Starter
4th Gear
Joined: Apr 2010
Posts: 4
Likes: 0
So just to be clear. All I'd have to do is disconnect the stock midpipe and...well...beat the cats to death?
Tech Contributor
Joined: Jan 2007
Posts: 19,341
Likes: 1,121
From: Dyer, IN
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Melting Slicks
Joined: Feb 2007
Posts: 3,266
Likes: 8
From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
For a stock mid pipe, you just unbolt the catback, unbolt the exhaust hangers on the rear bell housing, unbolt the bracket on the front section, remove the O2 sensors, and disconnect the exhaust manifolds. As far as the cats go...personally, I think it's a complete waste of time(not to mention destroying a perfectly good exhaust for a benefit that will only be measurable on a dyno)......so I can't speak to how to destroy the cats. Since you already stated that you don't want to hear "don't do it"....I figure you are dead set on doing it, and I might as well just support you.....
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Well,,,lets try this route. When you pound out the honeycomb catalyst,,,you leave behind a LARGE chamber. This chamber allows the exhaust gasses to expand and they become turbulent. You lose the laminar gas flow which will effect scavenging and reduce power.
On most NON ZO6 Corvettes, they installed a PRE CAT in the primary exhaust pipe just below the exhaust manifold. So,,now you have TWO cats to remove (four total) and four large chambers to lose power with.
Hey,,,its your car. After you find out that your exhaust smells a LOT worse after CAT removal, you didn't really gain any power and the exhaust note changed minimally,, you may find your self searching the INTERNET for an OEM CATTED Md pipe.
If it were me, I would save some cash and search for a nice used aftermarket exhaust system. You will be a LOT happier in the end.
BC
On most NON ZO6 Corvettes, they installed a PRE CAT in the primary exhaust pipe just below the exhaust manifold. So,,now you have TWO cats to remove (four total) and four large chambers to lose power with.
Hey,,,its your car. After you find out that your exhaust smells a LOT worse after CAT removal, you didn't really gain any power and the exhaust note changed minimally,, you may find your self searching the INTERNET for an OEM CATTED Md pipe.
If it were me, I would save some cash and search for a nice used aftermarket exhaust system. You will be a LOT happier in the end.
BC
Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
I checked my old stock exhaust. Ain't no way you'll get the guts out of the cats from the front or back end, unless you use a sewer snake or some other flexible looong device.
By the way what you're asking and suggesting in a public forum is a federal offense punishable by a $25,000. fine in any state. I'm just sayin.
By the way what you're asking and suggesting in a public forum is a federal offense punishable by a $25,000. fine in any state. I'm just sayin.
Burning Brakes
Joined: Apr 2008
Posts: 877
Likes: 4
From: Nouvelle Ecosse
Well,,,lets try this route. When you pound out the honeycomb catalyst,,,you leave behind a LARGE chamber. This chamber allows the exhaust gasses to expand and they become turbulent. You lose the laminar gas flow which will effect scavenging and reduce power.
On most NON ZO6 Corvettes, they installed a PRE CAT in the primary exhaust pipe just below the exhaust manifold. So,,now you have TWO cats to remove (four total) and four large chambers to lose power with.
Hey,,,its your car. After you find out that your exhaust smells a LOT worse after CAT removal, you didn't really gain any power and the exhaust note changed minimally,, you may find your self searching the INTERNET for an OEM CATTED Md pipe.
If it were me, I would save some cash and search for a nice used aftermarket exhaust system. You will be a LOT happier in the end.
BC
On most NON ZO6 Corvettes, they installed a PRE CAT in the primary exhaust pipe just below the exhaust manifold. So,,now you have TWO cats to remove (four total) and four large chambers to lose power with.
Hey,,,its your car. After you find out that your exhaust smells a LOT worse after CAT removal, you didn't really gain any power and the exhaust note changed minimally,, you may find your self searching the INTERNET for an OEM CATTED Md pipe.
If it were me, I would save some cash and search for a nice used aftermarket exhaust system. You will be a LOT happier in the end.
BC
Le Mans Master
Joined: Dec 2005
Posts: 8,546
Likes: 927
From: Communist Colorado
Dont waste your time or energy. The car will sound worse, run less efficiently, have less power & stink to high heaven. On top of that, you'll be polluting more than you need to. Just go buy a used set of hi flow cats and have them installed. Theres a right way and a wrong way to do things.
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
Just in case not enough people have told you not to do it, DON'T DO IT! I can only think of negatives in every case about this idea, on top of the fact you'll be wasting a lot of time to accomplish nothing. Be patient and do it the right way. At least give the A&A bypass mod a try. That might give you the result you want without screwing up your car.
