Keep Cats or ditch 'em?
Thread Starter
Melting Slicks
Joined: Dec 2004
Posts: 2,137
Likes: 5
From: Howard PA
Keep Cats or ditch 'em?
I drive my car very little and as such acquired an "Exempt" sticker, meaning I can do what ever I want emissions wise.
Would there be any benefit to ditching the Cats or just get some free flowing ones and stay compliant?
I'm ready to order headers and am torn between ordering the cat eliminator pipes or get the full cat set up.
Decisions, decisions...
Would there be any benefit to ditching the Cats or just get some free flowing ones and stay compliant?
I'm ready to order headers and am torn between ordering the cat eliminator pipes or get the full cat set up.
Decisions, decisions...
Safety Car
Joined: Sep 2003
Posts: 3,692
Likes: 5
From: Hayward CA
Several years ago, I ran with no cats for 1 day.....the smell of raw fuel was way too much for me. And, I really didn't feel much of a power increase. That being said, you're better off going with a hi-flow metallic substrate cat.
Burning Brakes
Joined: Jul 2005
Posts: 758
Likes: 6
From: Gainesville, FL
Living in Florida.. I would never drive a car with cats... that and my first car came from the factory without them... Even with my long tube headers - x-pipe and Flowmasters I still think mine could be louder... and I'm not smelling the foul smells other people are talking about either.... even if I did -- I tend to like that smell having grown up around race cars 24/7.
Last edited by 4REGT4; Sep 14, 2006 at 07:33 PM.
Team Owner
Joined: Jun 2001
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From: Orlando FL
St. Jude Donor '08-'09
I ditched my cats a LONG time ago. The precats both went a few weeks from each other and clogged the main cat. I then rammed out the main cat with a crowbar, so my exhaust is pretty much free flowing.
Also, I have never even once smelled the smell everyone tells me you will get from no cats (fuel or sulfer smell) and I have been running without them for 4-5 years now.
I do have to say, you pick up some nice breathability from loosing the main cat, or gutting it out. if you've never seen inside one, its just a honeycomb filter of chemical media (toxic, don't dispose of it in the ground) that I am not sure how the air even gets through effectively.
Also, I have never even once smelled the smell everyone tells me you will get from no cats (fuel or sulfer smell) and I have been running without them for 4-5 years now.
I do have to say, you pick up some nice breathability from loosing the main cat, or gutting it out. if you've never seen inside one, its just a honeycomb filter of chemical media (toxic, don't dispose of it in the ground) that I am not sure how the air even gets through effectively.
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Large Impressive Member
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by ALLT4
Aight, cats it is. Thanks for the input. 
I think it behooves us to be responsible in our hobby so we can enjoy it for sometime to come. Plus I want my granddaughters to grow up with clean air. Modern factory and aftermarket cats are nothing like the ones GI Joe describes. Properly sized in a well designed system, they'll rob virtually no HP.
Team Owner
Joined: Jun 2001
Posts: 26,196
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From: Orlando FL
St. Jude Donor '08-'09
Originally Posted by Corvette Kid
I think it behooves us to be responsible in our hobby so we can enjoy it for sometime to come. Plus I want my granddaughters to grow up with clean air. Modern factory and aftermarket cats are nothing like the ones GI Joe describes. Properly sized in a well designed system, they'll rob virtually no HP. The flow on the tiburon was soooo much better than the one on the Vette it seemed.
Modern technology rules! Wish I could afford a C5
Race Director
Joined: Jan 2002
Posts: 12,261
Likes: 85
From: O'Fallon Missouri
Originally Posted by GIJoe
I ditched my cats a LONG time ago. The precats both went a few weeks from each other and clogged the main cat. I then rammed out the main cat with a crowbar, so my exhaust is pretty much free flowing.
Also, I have never even once smelled the smell everyone tells me you will get from no cats (fuel or sulfer smell) and I have been running without them for 4-5 years now.
I do have to say, you pick up some nice breathability from loosing the main cat, or gutting it out. if you've never seen inside one, its just a honeycomb filter of chemical media (toxic, don't dispose of it in the ground) that I am not sure how the air even gets through effectively.
Also, I have never even once smelled the smell everyone tells me you will get from no cats (fuel or sulfer smell) and I have been running without them for 4-5 years now.
I do have to say, you pick up some nice breathability from loosing the main cat, or gutting it out. if you've never seen inside one, its just a honeycomb filter of chemical media (toxic, don't dispose of it in the ground) that I am not sure how the air even gets through effectively.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by Corvette Kid
I think it behooves us to be responsible in our hobby so we can enjoy it for sometime to come. Plus I want my granddaughters to grow up with clean air. Modern factory and aftermarket cats are nothing like the ones GI Joe describes. Properly sized in a well designed system, they'll rob virtually no HP. 
100%GI Joe - you removed a very poorly designed exhaust on that L98. I hate that design.
However, adding a pair of bullet cats to the pipes, an x-pipe and some nice mufflers might actually get that engine running better.
Team Owner
Joined: Aug 2000
Posts: 40,156
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From: San Pedro CA
Originally Posted by 4REGT4
Living in Florida.. I would never drive a car with cats... that and my first car came from the factory without them... Even with my long tube headers - x-pipe and Flowmasters I still think mine could be louder... and I'm not smelling the foul smells other people are talking about either.... even if I did -- I tend to like that smell having grown up around race cars 24/7.
It's about being concerned about the air we breathe, and the future for our children.
I am concerned that the collective ground level polutants will get so out of hand, that the EPA will mandate sniff testing in every part of the country. When that happens, well... I wouldn't want to be in your shoes.
Team Owner
Joined: Jun 2001
Posts: 26,196
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From: Orlando FL
St. Jude Donor '08-'09
Originally Posted by bogus
100%GI Joe - you removed a very poorly designed exhaust on that L98. I hate that design.
However, adding a pair of bullet cats to the pipes, an x-pipe and some nice mufflers might actually get that engine running better.
EEENNNteresting...
so the bullet style (I think that was what I was thinking of) came on cars from the mid 90's and later I am assuming?
Pro
Joined: Aug 2006
Posts: 682
Likes: 1
From: SpringHill florida
Originally Posted by GIJoe
I am guessing this is why the cat on my Tibby was so small (almost an inch larger around thant the rest of the exhaust pipe) compared to the super huge one on my vette and beater prelude. Interesting to know!!!
The flow on the tiburon was soooo much better than the one on the Vette it seemed.
Modern technology rules! Wish I could afford a C5
The flow on the tiburon was soooo much better than the one on the Vette it seemed.
Modern technology rules! Wish I could afford a C5
Race Director
Joined: Jan 2002
Posts: 12,261
Likes: 85
From: O'Fallon Missouri
Originally Posted by GIJoe
EEENNNteresting...
so the bullet style (I think that was what I was thinking of) came on cars from the mid 90's and later I am assuming?
so the bullet style (I think that was what I was thinking of) came on cars from the mid 90's and later I am assuming?
Burning Brakes
Joined: Jul 2005
Posts: 758
Likes: 6
From: Gainesville, FL
Originally Posted by Corvette Kid
I think it behooves us to be responsible in our hobby so we can enjoy it for sometime to come. Plus I want my granddaughters to grow up with clean air. Modern factory and aftermarket cats are nothing like the ones GI Joe describes. Properly sized in a well designed system, they'll rob virtually no HP.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by GIJoe
EEENNNteresting...
so the bullet style (I think that was what I was thinking of) came on cars from the mid 90's and later I am assuming?
so the bullet style (I think that was what I was thinking of) came on cars from the mid 90's and later I am assuming?
Team Owner
Joined: Dec 2000
Posts: 21,094
Likes: 282
From: Phila., PA burbs
Originally Posted by ALLT4
I drive my car very little and as such acquired an "Exempt" sticker, meaning I can do what ever I want emissions wise.
I also live in PA and also drive less than 5k per year which exempts us from emissions testing. I'm not sure where Howard, PA is but in my area of PA even though I'm exempt from the sniffer I am subject to a visual test. So if your area is the same as mine you could hollow your cat, but you can't remove it.
Burning Brakes
Joined: Jul 2005
Posts: 758
Likes: 6
From: Gainesville, FL
Originally Posted by TA
I also live in PA and also drive less than 5k per year which exempts us from emissions testing. I'm not sure where Howard, PA is but in my area of PA even though I'm exempt from the sniffer I am subject to a visual test. So if your area is the same as mine you could hollow your cat, but you can't remove it.