I’ve heard of a lot of people “gutting” their catalytic converters, what purpose(s) does this serve and how is it done? Does it increase power or torque at all?
It is just done by tearing out all of the insides of the cat and basically turning it into a straight pipe.
There are high rpm peak hp gains, but only at high rpm’s and you will notice a substantial loss of torque because there will be less backpressure with it gutted.
Personally, I dont think it is worth it. It is also really bad for the environment too.
If you want to get better flow through your cat then pick up a high flow.
Later,
BR
I wouldn’t do it again
One thing that B R didn’t mention is that your exhaust will STINK after you gut it. I always hated how I’d smell like exhaust after driving with the window open. The increase in performance is negligible. To say the least I’m very happy my ‘new’ DA came with a fully functioning cat.
However, if you feel the need then what I did was placed the cat upright on a concrete surface, rounded up a large hammer and chisel. Smash the ‘honeycomb’ porcelin out of the cat remembering to remove 2 sets of steel wool (one at the front, one at the back) with a set of pliers.
If you don’t like the gutted cat I’m sure you can pick a used one up for under $50.
Re: I wouldn’t do it again
Originally posted by DA_TEG
One thing that BR didn’t mention is that your exhaust will STINK after you gut it.
Yeah, I forgot to mention that part. It is usually common knowedge and I forget about it…
You gotta love the smell of nasty old rotten eggs coming out of your car. It is a real chick magnet, hehehe.
Later,
BR
Get a hi-flo cat. It will be obvious to cops that your cat is gone if you gut it. Loud and stinky exhaust= no cat.
If I WAS to gut the cat…I would try a straight pipe through it to keep the exhaust gasses in a straight path, rather than pausing to swirl around in the gutless cat. That way you’ve got a true straight pipe disguised as a cat. converter.
How do you know if your cat is clogged and it is time for a new high flow? I was told that because my 91 is over 10 year old that it is prolly time for a new cat. Is this true?
Originally posted by C.K. James
How do you know if your cat is clogged and it is time for a new high flow? I was told that because my 91 is over 10 year old that it is prolly time for a new cat. Is this true?
No not at all. Let me guess, a muffler shop told you that.
Somebody who has experience in this can usually tell by the amount of pressure coming out of the tailpipe. I had a non biased person quickly check this. Also, if you can smell the cat stink then it may be clogged.
As far as getting a Random Technology cat I wouldn’t do it considering they are relatively expensive and don’t yield much gains, however if you’re hardcore then do it up. At least you won’t get the stink of a gutted cat!
RASPY
One more thing. No matter what anybody says, when I gutted mine I noticed the exhaust note was substantially more raspy at all RPMs. Ear piercingly loud at high RPM. :roll:
my cat is still the original. 17 years old. i pass emissions fine.
Originally posted by DA_TEG
As far as getting a Random Technology cat
Dont get a Random Technology. They have a tendency to literally fall to pieces on the inside within a year or two of having it on.
Catco and Carsound are two very reputable manufacturers of high flow cats that I would recommend to anyone. The Random cat is just a waste of money.
Later,
BR
I have never noticed a stinky exhaust with my pipe cat. However, i have noticed that it is very loud at higher RPM’s. I used to love it, but whenever I take a long roadtrip it is very anoying. Now I am having trouble finding a cat at a reasonable price. I was supposed to get one from a friend for $10, but time passed, and now he doesn’t have it anymore. Oh well, just need to keep searching. My father in law swore that this was the best thing to do. I do think that there are some pretty good gains, but just hate how loud it is. It seams to be louder at the engine bay itself.
Don’t waste your time gutting the cat, cut the flanges off and weld them onto a 2-1/4" resonator, it’ll give you a lower exhaust note, cut out some of the noise,and only cost about $50 to have it done… Your car will still occasionally smell like gas from the lack of the cat but if you speed the hell up you won’t smell it…