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I was thinking about taking out the catalyst converter in my car and putting a straight pipe in. but i've noticed that in some cars doing this makes the car sound very trashy and i was wondering if ne one did this for an accord and if i could have some feedback on that
 

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Isn't that illegal? The catalytic converter removes pollutants and all sorts of nasty crap that otherwise gets expelled into the air. If you're looking to increase power or get a better exhaust note, there are other, more responsible ways to do it.
 

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It is illegal, Atleast it is in MD where i live. It may give you a raspy sound but i think thats more so with removing the resonator.
 

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8th Gen have 3 cats, the 3rd cat is just to make sure the 2 cats get everything out, the 3rd one is there just incase if the 2 miss something =D

Just take out the resonator and pre-muffler if your desperate for sound =)
 

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8th Gen have 3 cats, the 3rd cat is just to make sure the 2 cats get everything out, the 3rd one is there just incase if the 2 miss something =D

Just take out the resonator and pre-muffler if your desperate for sound =)
The V6 has three cats and the I4 does not. I have a V6 and I swapped my 3rd cat for a 2.5" test pipe. I am not sure what the options are for the 4cyl. but your best bet would be to get a good set of headers w/ a high flow cat. Or if you really don't care about the cat then get a race header. I am not sure if they even make headers for your car yet....

Another reason why you should keep your cat or a get a hi flow one is that it is illegal and you can get fined thousands, have your car impounded and be arrested.
 

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running test pipe/straight pipe with stock exhaust will make it sound raspy.
If he was to run straight pipes then there would be no factory exhaust. But, I do agree, your car will become really loud if you remove the cat and run straight pipes. Also, you must take into account that an engine needs back pressure to run efficiently. If you end up putting to free flowing of an exhaust on your car, you might gain high end power but your low end will decrease.

If you have the resources and the money I would invest in a good set of headers w/ a high flow cat coupled with a good exhaust. If there is nothing out for your car yet, you may have to have an exhaust shop fabricate it all for you. That way sometimes ends up being cheaper and you may get better results.
 

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you can't install headers on L4 or V6 cause the header is integrated into the head. All there is , is the primary cats mounted directly to the head .
AFAIK the secondary cat (3rd on V6, 2nd on L4) are clean up cats, they do clean up what the primary leaves.
 

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you can't install headers on L4 or V6 cause the header is integrated into the head. All there is , is the primary cats mounted directly to the head .
AFAIK the secondary cat (3rd on V6, 2nd on L4) are clean up cats, they do clean up what the primary leaves.
I don't believe that is true. The V6 models, have a small cast on header and after that is a "down pipe" that we call a precat. The cast on header is welded to the block and cannot be removed. But, anything after it can. The precats, the j pipe and the 3rd cat can all be removed. I have never seen a 4 cyl. made by Honda that has headers that are not removable. I know the 7th gen's headers could be removed and I am pretty sure they can be on the 8th gen.

The 1st cat on the 4cyl. is one piece with the headers. That is why when you buy race headers there is no cat. But, I'm sure you can get headers w/ a high flow cat in them. You may have to wait for the aftermarket support to catch up or have it custom made. He could just pick up a high flow cat for the 2nd one. Or he could put a test pipe w/ O2 simulators so as to not throw any codes.
 

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I4 with straight pipes = rice.

In order to get a good sound out of straight pipes, you'd need at least a V8. Either way, this is illegal and might actually reduce horsepower if you decrease the back pressure too much.
 

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I don't believe that is true. The V6 models, have a small cast on header and after that is a "down pipe" that we call a precat. The cast on header is welded to the block and cannot be removed. But, anything after it can. The precats, the j pipe and the 3rd cat can all be removed. I have never seen a 4 cyl. made by Honda that has headers that are not removable. I know the 7th gen's headers could be removed and I am pretty sure they can be on the 8th gen.

The 1st cat on the 4cyl. is one piece with the headers. That is why when you buy race headers there is no cat. But, I'm sure you can get headers w/ a high flow cat in them. You may have to wait for the aftermarket support to catch up or have it custom made. He could just pick up a high flow cat for the 2nd one. Or he could put a test pipe w/ O2 simulators so as to not throw any codes.
No, a header is a manifold of individual exhaust runners merging to the collector. there is neither on V6 or L4 any more, its just a way to mount the cat's (there no tunning available).
Where the cat's bolt up there is only 1 opening.

here both links to parts V6 an L4

https://www.hondapartsdeals.com/hpa...ionID=7&SectionID=1&IllustrationGroupID=16312


https://www.hondapartsdeals.com/hpa...ionID=7&SectionID=1&IllustrationGroupID=16311

Here is 2007 L4 for comparison, which has a exhaust manifold (header)

https://www.hondapartsdeals.com/hpa...ionID=7&SectionID=1&IllustrationGroupID=12113
 
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