Pre-Cats
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 179
From: S.W. Ohio. . . . . . NRA Life Member
Re: Pre-Cats (Yellow Coupe)
Does anyone know GM's reason for the pre-cats since the 01 models?
yes, because of the environ-
mentalcases
Did they improve emissions ?
only during a cold startup. Once the engine is at operating temps, the main cats do all the emissions work.
Did they hurt performance ?
If you look at the material they are composed of, you would gather that they are restrictive.
yes, because of the environ-
mentalcases
Did they improve emissions ?
only during a cold startup. Once the engine is at operating temps, the main cats do all the emissions work.
Did they hurt performance ?
If you look at the material they are composed of, you would gather that they are restrictive.
Le Mans Master
Joined: Aug 2002
Posts: 8,222
Likes: 0
From: Norfolk VA
Re: Pre-Cats (Mike Mercury)
so, is it worth the effort to take them out? Is it legal to take them out since they don't do anything once the engine is warmed up? would there be any performance gains to justify taking them out?
Melting Slicks
Joined: Feb 2002
Posts: 2,450
Likes: 0
From: Kansas City Missouri
Re: Pre-Cats (Lancer033)
Legal, no, but the car sounds better, and if you gut the existing pipes its impossible to tell youve done it without taking the car apart :D Maybe 5-10hp. Is it worth it? Its a free mod, and makes your car sound better, I think its worth it, not that ive done it :blueangel: :cheers:
[Modified by rrobert22, 12:48 PM 9/30/2002]
[Modified by rrobert22, 12:48 PM 9/30/2002]
Pro
Joined: Dec 2001
Posts: 530
Likes: 0
From: North Brunswick NJ
Re: Pre-Cats (rrobert22)
Does anybody make a flange pipe for a couple of bucks that replaces the Pre-cats? Doing headers for $1,300- $1,400 is a very costly way of going about getting my exhaust sound up. Already have the Corsa! :D
Le Mans Master
Joined: Nov 2000
Posts: 7,294
Likes: 1
From: Coral Springs Florida
Re: Pre-Cats (Traffic Hater)
Does anybody make a flange pipe for a couple of bucks that replaces the Pre-cats? Doing headers for $1,300- $1,400 is a very costly way of going about getting my exhaust sound up. Already have the Corsa! :D
Pro
Joined: Dec 2001
Posts: 530
Likes: 0
From: North Brunswick NJ
Re: Pre-Cats (vstella)
Thanks!
Question? I suppose this is illegal or at least voids cat system from GM?
Question? I suppose this is illegal or at least voids cat system from GM?
Does anybody make a flange pipe for a couple of bucks that replaces the Pre-cats? Doing headers for $1,300- $1,400 is a very costly way of going about getting my exhaust sound up. Already have the Corsa! :D
Lose the cats and get a straight through setup by Breathless Performance....Call Ernie at 954-925-7725 and tell him I referred you..He will know what you need.:D
Lose the cats and get a straight through setup by Breathless Performance....Call Ernie at 954-925-7725 and tell him I referred you..He will know what you need.:D
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 179
From: S.W. Ohio. . . . . . NRA Life Member
Re: Pre-Cats (Traffic Hater)
Does anybody make a flange pipe for a couple of bucks that replaces the Pre-cats?
here is the how-to page:
mikemercury.home.att.net/precats.htm
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Pro
Joined: Dec 2001
Posts: 530
Likes: 0
From: North Brunswick NJ
Re: Pre-Cats (Mike Mercury)
I can't believe they look for Pre cats, but I can imagine when I do the swap that day they will? Could the guy/gal really be aware of pre-cats??
Does anybody make a flange pipe for a couple of bucks that replaces the Pre-cats?
I wanted to do that; but in Ohio they do the visual inspection as well as the Gore tailpipe test. So I feared failing the visual inspection; and gutted mine instead.
here is the how-to page:
mikemercury.home.att.net/precats.htm
I wanted to do that; but in Ohio they do the visual inspection as well as the Gore tailpipe test. So I feared failing the visual inspection; and gutted mine instead.
here is the how-to page:
mikemercury.home.att.net/precats.htm
Safety Car
Joined: Mar 2002
Posts: 3,556
Likes: 2
Re: Pre-Cats (Traffic Hater)
You could always buy another four cat system, chop that up, and if dinged or need to go back to stock, swap back out.
I don't know what I would sell mine for (out of car now), or if I would...
I don't know what I would sell mine for (out of car now), or if I would...
Le Mans Master
Joined: Apr 2000
Posts: 7,218
Likes: 1
From: Cresskill NJ
Re: Pre-Cats (MiamiDave)
On an early C5 when there were just 2 cats can a long tube system be put on the car with the existing cats or is it necessary to go with aftermarket high flow cats?
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 179
From: S.W. Ohio. . . . . . NRA Life Member
Re: Pre-Cats (DngrZne)
I can't believe they look for Pre cats,
Cutting out the pre-cats and welding in a filler piece may look like the exhaust was tampered with.
I also thought of buying the 2002 Z06 H pipe which is minus the pre-cats and wouldn't look hacked-up. But for around $1800 shipped just for that section (Fichtners price).. I gave up on that idea.
vstella's idea is good; or you could buy long tube headers that tap into your existing H pipe, but past the pre-cats (they get cut off).
[Modified by Mike Mercury, 7:47 PM 9/30/2002]
Le Mans Master
Joined: Mar 2002
Posts: 7,179
Likes: 1
From: Honolulu Hawaii
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Re: Pre-Cats (Mike Mercury)
I can't believe they look for Pre cats, but I can imagine when I do the swap that day they will? Could the guy/gal really be aware of pre-cats??
Like most power-adder mod's we do, this is just another roll of the dice when it comes to passing smog tests. I thought the pre-cats were added MID YEAR 2001 so even some early '01's have none. My '02 has (had) them for sure...I just can't believe the minimum wage inspection dudes know the difference between production years of the Corvette. (No flames intended for min. wagers...gotta' start someplace).
[Modified by OCMike, 4:50 PM 9/30/2002]
Like most power-adder mod's we do, this is just another roll of the dice when it comes to passing smog tests. I thought the pre-cats were added MID YEAR 2001 so even some early '01's have none. My '02 has (had) them for sure...I just can't believe the minimum wage inspection dudes know the difference between production years of the Corvette. (No flames intended for min. wagers...gotta' start someplace).
[Modified by OCMike, 4:50 PM 9/30/2002]
Team Owner
Joined: Jul 2001
Posts: 21,335
Likes: 979
From: Various places in Southern California.
Re: Pre-Cats (Yellow Coupe)
I wouldn't expect the tester to know the correct cat configuration, but you never know. The actual test, though, should be easy to pass without the pre-cats, as the tests in all states I know of involve an already hot motor. The pre-cats are only there for cold start-up.
Pro
Joined: Dec 2001
Posts: 530
Likes: 0
From: North Brunswick NJ
Re: Pre-Cats (Duck916)
Man o Man I want to take those Pre-cats off! :crazy: If I have a gas station type of place do the inspection, am I better off! Heck, can Cartek do the snuff test! I'm not worried at all about passing, but am worried about the Gods saying I messed with the emission system! :blueangel: Maybe that will help! :blueangel: :blueangel: :blueangel: :blueangel: :blueangel: :lol:
Melting Slicks
Joined: Sep 2001
Posts: 2,501
Likes: 35
From: Sunshine State, USA
Senior Member
Cruise-In V Veteran
Re: Pre-Cats (OCMike)
I assumed my 2000 Hardtop had pre-cats, but when I was putting on my X-Pipe the other day, I couldn't see any. It just had the double walled pipe that runs from the exhaust manifolds to the real cats. So is is possible that the 2000's don't have pre-cats? Also, does anyone have pics of the pre-cats on the system so I can see what they are supposed to look like to make sure I don't have them? Thanks!
Race Director
Joined: Aug 1999
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From: Lackey, my own dragstrip VA.
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Re: Pre-Cats (Craig2000)
We have pre-cats on our 00' Coupe...............so far..................... :yesnod:
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 179
From: S.W. Ohio. . . . . . NRA Life Member
Re: Pre-Cats (ALLTHROTTLE&NOBOTTLE)
from what I've read; 2001 was the start of "model wide" precats. Before that, California bound cars were the only ones had the precats in 2000.
if you remember, the start of ther 2001 production year was when all Corvettes were "50 state cars"; meaning they all passed the Gore requirements in all 50 states. That was mainly due to the addition of the precats on all models produced in 2001 model year.
In 2002; the precats are not on the Z06 as they have more efficient main cats.
if you remember, the start of ther 2001 production year was when all Corvettes were "50 state cars"; meaning they all passed the Gore requirements in all 50 states. That was mainly due to the addition of the precats on all models produced in 2001 model year.
In 2002; the precats are not on the Z06 as they have more efficient main cats.
Burning Brakes
Joined: Aug 2001
Posts: 1,129
Likes: 0
Re: Pre-Cats (Mike Mercury)
All you gotta do is look in a daggone book I'd imagine. Some of the min. wage guys can likely read. The cars year and required equipment is right there, and the look it up usually.