Gutting the Cat.?

[Jordan]

Hey guys/gals,
Well im pretty shure the cat. is the cuase of my exhuast rattle. I have A 95' T/A with the single cat, and older computer. Some local guys tell me just take it off and gut it(they said with the older computer, it wouldnt bother performance, and sound better?)! I dont have to worry about emission checks here either. Im straped for cash, but if it really isnt a good idea please let me know. Ive heard this is good and or bad?
Thanks for your input
Jordan
saw a awsome 25thanv. driving today! man i love f-bodies!

[bru333]

This old thread might help you.

http://www.f-body.com/forum/showthre...hlight=gutting

When I replaced the engine in my car I found that the cat had been toasted by the old engine running rich. It had melted inside. Sounded like a baby rattle when you shook it. I replaced it with a catco high flow unit, from Summit. My '87 only has to pass a visual inspection here in nc, but you never know when that might change, so I went ahead and put a new cat on.

[pete]

My cat disintegrated at about 130k. It is easy to gut, open the flange just behind the cat, poke around inside with a large screwdriver to knock the ceramic honeycomb out of it, use a vacum cleaner or start it up to get the pieces out, reconnect the flange and your done.

It will not give you any outstanding performance of economy results, but will get rid of the rattle.

Don't do it if you need to pass emissions, replace it then.

[oldbutspry]

Careful....

Be sure to wear a dust mask when gutting it. I forget exactly what is inside, but I remember reading it is bad for your lungs.

[Injuneer]

Many people who have simply hammered out the ceramic substrate have complained that it gives the exhaust a "hollow" sound. And, having that big hollow "can" in the exhaust is not going to help flow. The prefered method is to insert a solid pipe in the can, after you remove the substrate.

[DeWynter]

I removed both from my 89, no problem, I realize your computer is different but, I belive not that different as yours is still batch fire like mine.

[Jay 02 TA ws6]

Many people who have simply hammered out the ceramic substrate have complained that it gives the exhaust a "hollow" sound. And, having that big hollow "can" in the exhaust is not going to help flow. The prefered method is to insert a solid pipe in the can, after you remove the substrate.

Right... sliding a pipe through the hollow can would be a great idea, and it would still look like you have a cat on the car, if by chance a police office wanted to take a look under your car.

There might not be emissions where you are (there aren't here either), but it is still highly illegal to remove and not replace a catalytic converter on a car that was designed to use them.

People who gut their cats typically end up with a pretty bad raspy sound, that sounds more like a ricer than a muscle car.

[Injuneer]

I removed both from my 89, no problem, I realize your computer is different but, I belive not that different as yours is still batch fire like mine.

Some bad info in this post.

No... his 95 is NOT batch fire like yours. The 93 was the last batch fire. 94 and newer are full sequential. Not that it is in any way relevant to deleting the cat.

The 4th Gen catalytic convertor bares absolutely "0" resemblance to the 3rd Gen....

3rd Gen is a 2-bed conveter, with intermediate, continuous air feed. 4th Gen is a single bed 3-way with no continuous air feed.

Comparing the two systems is meaningless.

[DeWynter]

My bad on the computer statement for some reason I thought that batch fire was up to 95. I stand corrected. The only thing I was getting at was that Removing the cat had no adverse affect on the drivability of the car, It really matters little on how the cat does its job be it a 2-bed converter, with intermediate, continuous air feed or a single bed 3-way with no continuous air feed. The true reason for the Cat is to reduce emissions. With no testing I see no reason to buy a cat but that is just me. Personally If it were me and I was concerned about tessting at a later date, I would just gut it and put in the tube.

[Jeff_in_Atl]

With no testing I see no reason to buy a cat but that is just me.

I would run a catalytic converter even if I didn't have to pass emissions. They are there for a reason. That is try and help keep the air clean so all of us can breathe. The honeycomb converters do not reduce the horsepower like the first generation of converters did. There is no reason to remove one that is working properly. If it is not working properly, replace it.

[Jay 02 TA ws6]

I would run a catalytic converter even if I didn't have to pass emissions. They are there for a reason. That is try and help keep the air clean so all of us can breathe. The honeycomb converters do not reduce the horsepower like the first generation of converters did. There is no reason to remove one that is working properly. If it is not working properly, replace it.

Hippie

[Jeff_in_Atl]

Hippie

I used to have a "Mullet". Does that count as a hippie? I've been called lots of things in my life but never a hippie. LOL

Hunters are very conservative people and they are the biggest environmentalist there is. Liberal say they are environmentalist. Conservatives are environmentalist.

[Injuneer]

I would run a catalytic converter even if I didn't have to pass emissions. They are there for a reason. That is try and help keep the air clean so all of us can breathe. The honeycomb converters do not reduce the horsepower like the first generation of converters did. There is no reason to remove one that is working properly. If it is not working properly, replace it.

I'm with you Jeff. When I built the engine, and the car was street driven, I maintained the full emissions equipment - dual 3" high-flow cats, EGR, EEC, AIR and PCV. It took extra effort and money to do this, having to integrate the stock PCM for emissions controls with the aftermarket MoTeC ECU.... dual sensors, artificial signals, etc.

When I got all done, I had an 800HP setup that would pass NJ rolling emissions. It would not pass visual, since I added a cat, and a few of the parts were not CARB certified.... but the tailpipe was "clean".

Lingenfelter claimed there was no more than 5HP loss on one of his higher HP emissions certified cars due to the cats.

Taking the attitude that its OK as long as no one checks up on you is pretty selfish, IMHO. I'd like to see the racing sanctioning bodies adapt emissions requirements for the "stock" and bracket class cars. They've already gone to mufflers in many classes.... maybe adding emissions requirements would require a littlel creativity, but I'd support it.

Hippie.... tree hugger..... yep

Fabbing the 3" dual-cat Y-pipe......

[Joe 1320]

I have to agree...... I went a more expensive route using SLP headers and Random Tech high flow dual cat Y pipe. I gained a noticeable amount of power and the car is 50 state legal. Stuff like that really does make the overall quality of your ride better, especially in the resale at a later time.

[TruckMuddr]

Since we are talkin about cats is there any advantage in converting a single cat system to a dual cat????