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Discussion Starter #1
I have a 2000 2.5rs With a cobb tuning intake, stromung midpipe, magnacore wires, and borla headers. I was thinking about removing the cats, or boring some other cats out for when I go to race. What affect would this have? Positive negative. All input is welcome.
 

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Well I guess I will be the first... I have no cats on my car as of right now and I love it. Im not exactly sure what the emission laws are where you live, but where I live it is fair game. Before I ordered my Catpipe from Rallispec I decided to bore out my cats. Very very bad idea. I would not recommend this one. Not only was it a pain, but also it made really irritating noises. It almost sounds as if someone list a firework in a pop can, it is really annoying. If you are going to do this, I would just hollow out the flatter cat (not sure if it is the first or second). Leave the larger balloon looking one alone. I myself would just get rid of the pipe altogether, I have been happy with my Rallispec pipe since the day I bought it.:) :sunny:
 

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Discussion Starter #3
No check engine lights or anything? and could you explain a little more about the rallispec pipe. :happynow:
 

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Sorry, I failed to mention that you will get the CEL, but it really isnt that bad after a while. The only bad thing is that you wont know if something else goes wrong unless you get a critical at which the light will start to blink like crazy. And about the rallispec pipe, very very nice. It is a 2.25" pipe with a piece of flex tube on the rear section. All of the welds were very nice and precise. The only problem that I had with it when I first got it was the placement of the O2 sensor in the front, they didnt tap it deep enough so I had to dremel it, but it worked great. I would seriously recommend getting the Rallispec pipe. I believe that I paid $250 for it, but that was like a year ago. Im not even sure that they make them anymore, but it is worth a try. One bad thing is that it is made on request only, so it takes a pretty long time to receive it (2 months).

Hope this helps:)
 

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People have said that they get better powergains with cats, but I think that is false myself. After I had my cat-eliminator on for a few months (I was bored one day) I decdied to throw my cats back on and see the power difference. Blaaaa. It sucked. I took it for a drive for like 20 minutes, went home again and threw the cat-eliminator back on. People have claimed to have lost alot of low end power, but I dont see it. It might all depend on the exhaust system as well. I have an Arospeed Bomb Exhaust with an SPT mid pipe. One other cool thing about no cats is it makes you ride into a REALLY SNOTTY SOUNDING SUBY!! (Some of that has to do with the Borla Header though, I had a friend with no cats and no borla header and his car sounded weak) :) :)
 

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Im not really sure if boring out the flat one is the one that triggers it or not. I think that I remember someone saying that the first O2 is the one that triggers the CEL, but I am not for certain. So if the flat O2 is in the front (which I think it is), you will probably get the CEL.
 
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your friend

so if your friend had no cats? he ordered the test pipe from rallispec? anyone else with any other suggestions? and which cat do you all hallo out? anyone really know?
 

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Discussion Starter #10
From what it sounds like boring out the cat isn't that great of an idea. Ive did it on other cars, and it usually results in a pretty bad sound. I think. I will either go with the random tech cat, or a complete test pipe such as doodies from rallispec
 
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so whats the diffrence between a High flow cat, a full cat back, and no cat.. and a test pipe?
 

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Discussion Starter #13
A test pipe is just a pipe between the header and the mid pipe. It has no cat on it, just o2 sensor bungs. A high flow cat on our car replaces both of your cats with one piece that has higher flowing capacity, (less obstruction I guess) A cat back exhaust does not replace the cat, it just bolts to it. and replaces the midpipe and the rear section.
 

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summit racing sells catco cats. I think they retail for 50 bucks. take that to a local muffler shop and have them bend you some piping, the whole thing would probably cost ya about 100 bucks.
 

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Discussion Starter #16
boring out the cat usually involves throwing it in a vice or someting. And taking a drill or a chissel to the honey comb stuff inside. (ripping all of it's guts out) Making it a stratight through pipe.
 

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Discussion Starter #18
hmm I honestly wouldnt know. It could be more of a mind thing. Up top of course the exhaust is going to flow more freely, creating more power. But down low, the back pressure is nice to have. It's a toss up. 1-2hp maybe more maybe none.
 

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well.........I just hollowed out my cats..(had another pipe on hand)
lemme tell you!!!!!!!! The performance is awesome,,,the sound is down right irritating!!!!!!!!!!!
REAALLLLLLLLLLLLLLYY SHITTY!!!!!!
wasn't that hard to hollow them out though...no CEL, smelly as shit
gonna try a test pipe tomorrow
 
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