gutting out the catalytic converter

alright...about a month ago i bought a 94 z28...everything on it is stock...i plan on buying a flowmaster muffler very soon...but there is one thing i want to do before i put on a muffler, and that is to gut out the cat, because i want it to be loud. As you know the catalytic converter is pretty much a box sitting up under the camaro..and on my old v6 i took it off one time and looked at it and it had been gutted out because it was quite loud for a 6 cylinder...so what i want to know is...does the converter have chemicals in it that makes it so quiet? or can you simply use a coat hanger and gut it out? from what everyone has been telling me?

???

There is an actual physical catalyst inside, it can be knocked out.

thanks alot man...i did see the catalyst...it's like a honeycomb looking thing...i chipped some of it out but i would like to do it without it falling out inside the cat....i cant fully take if off because part of the cat is welded to the pipe which isnt good

The ol' gutted cat and Flowmaster combo. To be young again. :)

Gutting the cat causes funky air velocities that do not help to increase power and actually make the exhaust sound bad. Pull the cat and install a bullet muffler.

mine are gutted w/ a stock manifolds to magnaflow catback w/ 3" cutout. Sounds wicked w/ the 3" cutout just idling, especially when I first start it up. W/ the m6 its real fun to drive you can control the amount of noise you want to make.

why not just take it off and have someone put a piece of pipe in its place:confused:, when i first got my car i had my cat gutted, a month later i had it removed because it sounded terrible

If you want your cat gone that bad, put a piece of straight pipe in its place. By simply gutting it, the air velocities get screwed up as the exhaust passes through what is now a big open chamber and tries to find its way out the other side.

Straight pipe in place of the cat will give it more volume without hurting anything else. However, there isn't a HUGE gain to be had by gutting it, simply for sound.

yea a friend of mine did mention putting a straight pipe on...the thing is, is that the pipe is welded at the front of the cat leading up to the engine which means ill have to cut it off...i just dont want the chance of messing it up and having to weld it back together

come on now, there is going to be some gain by gutting the cat vs. not. Obviously, despite the air getting moved around. I'd say its good for a couple hp at the top end.

come on now, there is going to be some gain by gutting the cat vs. not. Obviously, despite the air getting moved around. I'd say its good for a couple hp at the top end.

not really, with a intact cat the air at least flows where it is supposed to, once it is gutted the exhaust flows into a empty chamber where it bounces all over the place trying to find its way out, but either way theres probaby not much of a difference in performance

needless to say I didn't gut mine a previous owner did. I personally would not take the time to do it, rather get an offroad y pipe. But since it was done already, I can't complain.

the thing is...i'm not even looking to do this for performance...i just want it louder...i like the raspy sound personally...i'll move to performance later on down the road...i plan to keep this car a long time and im actually considering turning it into a drag car later in the future

not really, with a intact cat the air at least flows where it is supposed to, once it is gutted the exhaust flows into a empty chamber where it bounces all over the place trying to find its way out, but either way theres probaby not much of a difference in performance

If a cutted cat hurts velocity, then I imagine a closed cut-out would to the same. A 3" wye with a cap on the branch is going to cause some disruption then too. (My theory)

my question is...is when it comes to knocking out the catalyst...what is the best and easiest way...because i have been out working on it and it just keeps chipping off in little pieces

I took a piece of pipe and beat it into the catalylst. Then I would start the car to blow out the chunks. It took a little while, and made a bit of a mess in the driveway.

You may want to be careful, i heard about some of the dust from the catalyst containing some crap thats bad to breathe in, so i'd wear a dust mask and pound away.

I took a piece of pipe and beat it into the catalylst. Then I would start the car to blow out the chunks. It took a little while, and made a bit of a mess in the driveway.

yea a friend of mine suggested that about blowing out the chunks by running the car...i thought he was being sarcastic though..lol...but anways thanks for the advice

another question...does the catalyst go all the way through or is it just a thick wall because ive been pounded the crap out of it and it's making some progress it just seems so thick

It go's all the way through..

Its thick as hell good luck getting it out w/ out dropping the ypipe.

just got done knockin it out...took about 2 1/2 hours...it's definately a little louder...now all i need to do is slap a flowmaster on next week and i'll be set :D

i use a 16'' flathead screw driver that has the handle broken off,and a big hammer.you can also use the screwdriver to prime your oil pump on your next rebuild.

I used a floor jack handle/lever and a hammer. It did take some work.

Gutting the catalytic converter without putting a pipe through it will make your car sound like crap. Take a piece of 3" pipe, run it through the casing, and have the casing welded to the pipe. In the end, it looks like a stock catalytic converter, but it's really a straight pipe - the best of both worlds.