02 GT cat delete question

austindorow

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Mar 20, 2019
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has anyone ever cut out the second from front cats on a 2v, hows it sound, and will it throw codes, my current setup is stock cats with offroad h pipe no muffler. the ones i want to cut out are circled. thanks
 

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Noobz347

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Sound isn't much of a consideration unless you're a Honda.

Performance on the other hand, will suffer. Your pre-cats and cats are 2-way. They work together and don't duplicate each other's process. You will throw a code. It will run like crap without a tune (because it's currently tuned to [have] them), and generally stink up car and garage with no benefit.

Build horsepower. The sound will take care of itself.
 

austindorow

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Sound isn't much of a consideration unless you're a Honda.

Performance on the other hand, will suffer. Your pre-cats and cats are 2-way. They work together and don't duplicate each other's process. You will throw a code. It will run like crap without a tune (because it's currently tuned to [have] them), and generally stink up car and garage with no benefit.

Build horsepower. The sound will take care of itself.
Thanks for the response, I am running a bama chip tune from American muscle and only cai, would that help any? I’ve seen people from my Instagram talk of doing it and from a little if I had read online people made it out to seem ok, but what you’re telling me is not to mess with any of the cats at all even just the second ones closest to the rear wheels?
 

Noobz347

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I'm saying don't mess with a 'tuned exhaust' system at all unless you have a plan. Hacking and slashing is for... I dunno what.

Go through that car with a fine toothed comb and make every single thing is in working order and in good repair to include brakes and suspension.

Then, go out and find a supercharger kit. Leave the exhaust right where it is.
 

austindorow

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I'm saying don't mess with a 'tuned exhaust' system at all unless you have a plan. Hacking and slashing is for... I dunno what.

Go through that car with a fine toothed comb and make every single thing is in working order and in good repair to include brakes and suspension.

Then, go out and find a supercharger kit. Leave the exhaust right where it is.
Sounds good man, it’s a good loud where it’s at now anyways might as well not mess with it but already in the process of making it mint, just the down side is finding a way to really build the 2v :/
 
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Noobz347

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Get a blower that give you growing room. By the time it is installed and tuned, you will know [exactly] what the next weakest link in the chain is whether that's gears, exhaust, heads, what have you.

Make sure the engine is in good shape, install the blower, make it right, then go from there. It can be a big chunk at once it's better than wasting money and time on junk mods you'll have to 'undo' later for even more money.
 
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I wouldn't quite call it a tuned exhaust system with the manifolds that come stock. You might see a slight increase in power (not really measurable for the most part) and as far as throwing a code, I would seriously doubt that eliminating one cat would throw a code considering the margin of error that OBD2 has for slight differences in oxygen content in the exhaust stream. Modern day sensors (5 wire) are much more capable of seeing these differences, but for the most part that last cat isn't seeing much NOx emissions by the time the exhaust reaches it. You'd be safe to remove them as long as you don't have a visual inspection done by some over-zealous tech. As well, not trying to "call out" anyone with the tuned exhaust comment, the sentiment is correct with losing power but it really only applies to mufflers because they act as a damper for pulses of air entering them and tend to smooth out turbulence in the exhaust system; think of a muffler like a bucket of water and piping as a cup, dropping water into a bucket is going to jostle the water around less than if you do the same to a cup of water.