mobomelter
Member
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- 2004 Civic Si
usually they put at least 1 o2 sensor before and after the cat. i have no idea what they've done on the 3 since i haven't been under it yet.
High Flow Cat
- Thread starter chrisyoung10
- Start date
mobomelter
Member
- :
- 2004 Civic Si
please read carefully before you insult someone. i said "usually" meaning on most cars i've seen. also i specifically said i had no idea what they've done on the 3. please read things before you make conclusions.mobomelter said:
the o2 sensor is before the second cat, and yes you will get a little hp/tq out of it when you take out the cat, however, if you have CAI, header, and free flowing exhaust you get a noticeable difference. You won't feel a tremendous change by changing one thing, but as a whole it is a great gain. But going back to the topic, after I took out my second cat, I felt a noticeable change in power in mid range(3000-6000 rpm).
goldwing2000
OG Mazda Mafia
- :
- 2004 Mazda3s Hatch; 346,000 mi (sold)
2024 CX-5 CE; 7,500 mi (so far)
AzMz3 said:
Herb, you were kind of an asshat about it. Try to be a little more civil, k?
saskmazdaman11
Member
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- 2004 Mazda3 Sport GT
Solution
There are so many ways to run a cat illeagally, but still have the illusion of being legal. Those damn catalytic converters are so fragile, when you "accidently" drop them numerous times on concrete and then all the guts fall out. Or when you accidently cut the cat open and run the exhaust through it by mistake.
You may not pass an actual emmisions test, but it should pass a visual test.
There are so many ways to run a cat illeagally, but still have the illusion of being legal. Those damn catalytic converters are so fragile, when you "accidently" drop them numerous times on concrete and then all the guts fall out. Or when you accidently cut the cat open and run the exhaust through it by mistake.
You may not pass an actual emmisions test, but it should pass a visual test.
Guys, can someone clarify this discussion.....here's what I'm getting out of this...with the Hiflow cat you wont notice hardly any diff, unless you have the intake, exhaust, headers, etc...once you have all that then the diff is there....Also, does the hiflow make the note ricey?????
goldwing2000
OG Mazda Mafia
- :
- 2004 Mazda3s Hatch; 346,000 mi (sold)
2024 CX-5 CE; 7,500 mi (so far)
tgv121281 said:
It's the same story with any minor modification. If you do one small thing, it will help. If you do other things related to that one thing, it will help more. It all depends on how much money you want to spend and how much you want to dig into your vehicle.
With regard to the note, a catalytic converter is a HUGE exhaust restriction, so it seriously deadens the exhaust noise. By putting on a high-flow cat, you are decreasing the restriction, thereby allowing more noise through to the rest of the exhaust system. Without the right muffler, this could end up sounding like a fart can.
Greenbread
Member
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- Mazda 3s
so if i get an cai, high flow and a catback it wold sound good?
mobomelter
Member
- :
- 2004 Civic Si
as goldwing said it depends on the muffler. my focus had headers, a high flow cat, and cat back exhaust. it sounded ricey but a resonator can fix the rice sound.goldwing2000 said:
I can testify to the FACT that the 3 will sound RICEY with CAI, no cat, and 2.75in pipping straight through a muffler....(If i get a digital camera, maybe than I can let you hear and see what it sounds like. RICE! Yes I admit, it is really loud, and a little ricey)
CarbonMz3 said:
From the 2.75" exhaust I take it you have a custom one.
I'd agree if you go out to be cheap and get a crush bent exhaust with only a muffler and remove a cat, yes it will be pretty loud and sound bad.
The cats actually quite the exhaust down alot. I know when I added a off-road pipe to my Focus it was loud and pretty bad.
yeah but I ordered mine as all 1 piece, so why would it not be the "right" muffler??? not trying anyone, just dont really get it...if I order a catback system--I expect the pieces to be right for each other,(muffler, cat, piping)...I dunno, too late to cancel anyway so I'll just have to put it on and see whats up w/ it....I have a cai as well...so at least even if it sounds bad I'll have a pretty well breathing engine..till those headers finally come out!
