well, i finally have a free saturday so i thought why not gutt my cat. i know alot of people on this board have done it, so i was wonderin if you had any tips on how to remove the crap thats in there. Heres what i know so far, i need to remove it and then start stickin a srcrewdriver in there and try to loosen upo chunks of whatever the interior of the cat has. how long should i be bangin on this thing? is a screwdriver the best tool for this job? what exactly does gutting the cat do for performance? will i notice a differnence at all? i have already passed smog so im not worried about the legal ramifications yet.

thanks alot

daniel

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86 camaro cpe(dont laugh)has 92z28 body kit with GTS covers, new red paint and a killer stereo. 2 amps, 8 speakers, disc changer, custom install with subs coming by the end of the summer. sawpped (or in the process of) 305lg4 for brand new 350. TES headers, flowmaster cat back, performer manifold, TCI converter, jet chip, kn with dual snorkel cleaner. and she still passed the sniffer!

"Cal Poly SLO is the shi#"

 

Eh Why Not Just make a little peice of pipe to replace it?


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85 Z28 - Daily Driver
60 Ranchero - Project ( Money Hole )

 

Performance gain will be minimal at best unless the cat is clogged in the first place.

Since you just passed smog, what about 2 years from now or when you sell it.??

Not trying to discourage you in any way, I would just put a pipe in place and hang onto the cat for future use.

Alot of cars pass smog with the cat gutted but the more you mod, the more you need the cat to hide the modifications. (as far as "out the pipe" is concerned)

There have been dyno runs (I can't find the article...DOH) that show the engine in question made MORE power with a high flow cat than it did without it.....

Something to think about.

To answer your other question, a big screwdriver or a long socket extention will do the job well with a big hammer and some patience.


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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

GO #3

[This message has been edited by Engineboy (edited November 08, 2000).]

 

make sure that you get a heated O2 sensor or you will have computer problems. gutting the cat makes it loud i like mine gutted, they way it should be

 

Appearances are important in a smog check! Here's the quick way to gut a cat. Take a piece of exhaust pipe that will just fit in the cat pipe. Take a hammer and drive it through to the other end. Pull it out and you will be rewarded with a clean, cored out cat conv. Cored out just like an apple. Now, put it back in!!! Air injection pipe and all so it will pass the appearance test.

 

that exhaust pipe idea is a great one, i shall search the area for one that will fit. does a gutted cat make the exhaust louder? if so, is it loud enuf to cause a ticket?

thanks

daniel

 

havent performance cats just about as good as not having one at all?

 

What computer problems? I've had a gutted cat in my 92 Z28 convertible for about 3 years and it has never thrown a code! I felt a big improvement when I put the gutted cat on this car. And no, the cat was not clogged, it had about 10K on it when I pulled it. I also passed Florida emissions with this car. Plus with a alum drive shaft, Dynomax catback, hollow cat I ran a best of 14.21@96mph. She runs 14.5's all day. That stock 5spd, centerforce clutch, 3:08 posi rear w/Eagle GA's.

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Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Gutting these straight-through monolith cats won't make your exhaust a whole lot louder.

In the bad ol' days of pellet-bed converters, you had to knock out the case plug, knock a hole in the perforated bed, and drive for a while over a bumpy road to blow all the pellets out. Then you put the plug back in. The exhaust would be noticably louder after that. Those old cats were so awful that even the worst low- compression smogger would run better on the highway after doing that operation!

 

how old were those "bad ol' cats" cuz mine is from an 86 cpe.

thanks

daniel

so bottom line, should i or shouldnt i gut it????

 

a strait pipe works good,however a good cat back sytem(like borla with open plate) will allow good highway performance then you can still keep the cat

 

I would replace the cat with a pipe. But, I don't have to deal with any smog checks. It sounds good (some sounds on my web site) and runs great.


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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

If You replace the Cat with a pipe, its as simple as Putting the cat back In 2 years from now to smog, thats like a 30 minute job if you hve the bolt In Kind.

On My motors, I usually Take off the EGR, the Cat, the Air Pump, Plug the air Injectors into the manifold, Disconnect the ECS and essentially every other Emissions part and Chuck em In a box, then when that time comes around, Pull the box out of the closet marked "85 Z28" and make a half Day of putting all the **** back on.



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85 Z28 - Daily Driver
60 Ranchero - Project ( Money Hole )