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Old Aug 6, 2007 | 08:53 AM
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Default Gutting Cats

Was Thinking About Gutting My Cats. Anyone Have Any Thoughts On This?
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Old Aug 17, 2007 | 07:15 AM
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I have a set that will be coming off my 98' SS here in a couple of days. The car only has 55,000 miles. I'll sell them to you if you are interested. This way, if you don't like them, you can always throw your old ones back on.

Let me know. I will be selling them for $175 shipped.
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Old Aug 29, 2007 | 11:40 AM
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I Had the same post and I was told I would I would run rich and need a tune.
Plus I would,
1.get worse gas mileage because of running rich
2.have smelly annoying fumes because of runnning
3.lose performance because of running rich
4.get the dreaded service engine light
5.throw out black smoke because of running rich
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Old Aug 29, 2007 | 02:27 PM
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the o2 sensors that are responsible for the a/f of the car are ahead of the cats...how would gutting them affect the a/f??

you don't even need a tune after headers...other than codes which still don't affect power.

YEAH you'll gain power with a tune after headers, but probably 90% of that power gain would be felt from a tune on stock manifolds/cats.
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Old Aug 29, 2007 | 06:52 PM
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So what I was told was wrong? I know for a fact on the 98 and 99 ls1s that their is a o2 after the cat on the passener side but they o2s are both before the cats on an 00-02.
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Old Aug 29, 2007 | 08:21 PM
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All OBD2 LS1 f-bodies have an O2 upstream and downstream of each cat, so you have a total of 4 sensors. The 2 ahead of the cats regulate the fueling, the 2 post cat sensors make sure the cats work. You can delete the downstreams with O2 sims or just edit them out.
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Old Aug 29, 2007 | 09:37 PM
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gutting the sats will only net you.....MORE power and a louder sound....you will smell all the unburned fuel that comes through the exhaust....

therer was a thread a month or so ago where a guy done back to back dyno runs and gained 10rwhp by gutting cats.....and it will not affect a/f ratio
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Old Aug 30, 2007 | 01:25 AM
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Gutting the cats in no way will affect your a/f. Although I think it is better if you just cut the cats off completely and weld in some straight pipe. If you take it to the right place they will do this for you, it only cost me $50 and I already had 02 sims due to my SLP high flow cats that stopped working after 3k miles.... go figure...
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Old Aug 30, 2007 | 02:11 AM
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Originally Posted by 5_02ls1
gutting the sats will only net you.....MORE power and a louder sound....you will smell all the unburned fuel that comes through the exhaust....

therer was a thread a month or so ago where a guy done back to back dyno runs and gained 10rwhp by gutting cats.....and it will not affect a/f ratio

x2 I guted the cats for a while then went with LT's and TD's
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Old Aug 30, 2007 | 08:17 AM
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Just keep them the way they are until you put on headers. When you install the headers you can sell them to a scrap place for 70 bucks a piece. Thats what I did, it helps take down the price of the header install.
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Old Aug 30, 2007 | 08:24 AM
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Originally Posted by 98Camarod
Just keep them the way they are until you put on headers. When you install the headers you can sell them to a scrap place for 70 bucks a piece. Thats what I did, it helps take down the price of the header install.
Or hang on to them in case some bad smog inspection laws are passed in your state, or you move to CA.

They have some practical or monetary value intact; gutted they are worthless.
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Old Sep 5, 2007 | 09:47 PM
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ive been there.car ran like ****.rasp.lugged while daily driving. dont do it.
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Old Sep 5, 2007 | 10:16 PM
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Originally Posted by Drew's TA
Gutting the cats in no way will affect your a/f. Although I think it is better if you just cut the cats off completely and weld in some straight pipe. If you take it to the right place they will do this for you, it only cost me $50 and I already had 02 sims due to my SLP high flow cats that stopped working after 3k miles.... go figure...



+1
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Old Sep 6, 2007 | 12:44 AM
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Originally Posted by Drew's TA
Gutting the cats in no way will affect your a/f. Although I think it is better if you just cut the cats off completely and weld in some straight pipe. If you take it to the right place they will do this for you, it only cost me $50 and I already had 02 sims due to my SLP high flow cats that stopped working after 3k miles.... go figure...
im thinking about doing something like that but instead of welding a pipe get a bolt on pipe so when emission time comes I can just bolt them back on
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Old Sep 6, 2007 | 10:05 AM
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I did this to my car and it felt like I lost low end torque. I ended up putting a stock y pipe with cats back on until I got my headers. I would just tell you to get an ORY pipe which could be had for cheaper than your cats are worth. Here is what I recommend.

1) Take off your y pipe and cut the cats out. Sell them for the guaranteed $140 shipped that they are going for in Wanted Section.

2) With that extra cash you can just buy you an ORY pipe that will fit the stock headers. Its bigger piping and you wont have to deal with the swirl effect that a gutted cat creates.
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Old Sep 6, 2007 | 10:22 AM
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02 Sims? Whats that i've been running with my check engine light on due to the same damn code.
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Old Sep 6, 2007 | 11:44 AM
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Lots of bad information in this thread. Pulling your cats off is not going to hurt performance, period.

I wouldn't gut them either. As was said above, pull them and sell them.
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Old Sep 6, 2007 | 04:02 PM
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Gutting the cats won't get you anything. Any reduction in restriction will be offset by the turbulence created by the exhaust having to flow through the open cans you made the cats into. Cats on newer vehicles are quite efficient usually only costing you 5 hp or so. If you want to remove them, make a pipe to replace them. The louder exhaust will make you think the car is faster.

Re'
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Old Sep 6, 2007 | 04:55 PM
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good info due to experiance... gutted cats will not gain you in performance and daily driving.. i agree totally with reandcheryl above ^^^^^^^^^^
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Old Sep 6, 2007 | 05:34 PM
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Gutted cats = pointless
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