bump,i would like to know as well as i'm trying to learn about the eclipse all i can.my mazda had 2 cats (4-c),1 with an o2 sensor,1 without.i got rid of the one that didnt have an o2 sensor.so,i really need to know if there is just 1 cat on my 09 gs ? please help a brother out with some info lol.cause if there is 1 without an o2 sensor,i'll be removing it asap to let my engine breathe.cant stand a clogged up exhaust sysyem.please advise !!

 

I dont know about the 09 configuration, I would imagine it would be the same, but none of the o2 sensors are actually on the cat's. You can buy an aftermarket header, like RRE's, and have no SES lights on.

 

There is 3, 2 on the stock header and 1 on the exhaust

 

thanks for the info guys !! so if i'm understanding this right.there are 3 cats,1 resonator,and a muffler.this is correct no ? talk about a restrictive exhaust system lol.i will be removing the 3rd cat and replacing a resonator in its place for now.it should be the first thing i see before the resonator right ? just want to make sure its the right one before i have them take it out.

 

2 cats on headers, 1 cat on exhaust. magnaflow high flow cats r beast

 

Did you ever get that 200-cell one I showed you? If so how do you like it? Notice any difference at all?

 

^ omfg bro it is awsome. sound is fuking amazing. u can feel less restriction

 

Woooord. I'm glad you got it, because I was on the fence and when you said you were getting it I was like, well damn I'll just let him be the test dummy ; )

 

And what size did you get? I think there was like a 8" 2.25 and a 10" 2.25

 

u can get any size up to 14" length. i got the 8" so i could replace my rusty pipe with a nice new section pipe plus its a smaller converter

 

Woooord....

 

the one i got is part # 59955

 

Yeah that's the one I was lookin at....