rosendo192000

i have a question about uninstalling my cat off my (01 pro)

my question is ,would it increase loudness dramatically on my car
,and is the sound of it noticeable

thanx
_robert
_01 pro es

tresdos3

was there a noticeable difference? eg. seat of the pants

cause there have been a few comparo's done recently which allude to the fact that hollowing out the cat on newer models may not give u any noticeable difference.

just wondering?

01esgt

SInce the 2.0's have 2 cats i guess he took out the second one. Was there a o2 sensor back there? cause ive been contimplating doing the same?
Joe 01 ES GT

tester

No o2 sensor after the primary cat. There are 2 o2 sensors (odbII spec), one before and after the primary cat. I believe the 1st sensor is what the computer reads to set the fuel, and the 2nd is just to make sure that the 1st is working (2nd is just a "yes" its working signal). If I remember right about odbii cars......
Usually when you pull out the primary cat, you put 1 o2 sensor on, and do a jumper on the 2nd o2 sensor (put voltage to the sensor to "prove" to the computer that the 1st one is working.
If I were you, I would not pull out the secondary cat until
a. you get a cat back system
b. you get a new exhaust header that has no primary cat.

Hopefully someone will offer a 2nd cat "racing" tube that we can just order. I hate going to my local muffler shop and trying to get something custom made.

Hopefully your province/state has no emmision testing..

01esgt

i know on mazda motorsports, there is a header besides the world challenge header available for like 400 us. we should see if we can do anything with this or gain access to it as only registered racing persons have access to this stuff

RebelRacing

One question I have regarding this cat stuff is regarding the way many Hondas are done. I think the Hondas have 2 cats aswell...when you install a highflow/performance cat will a single cat work as well as 2? If so, what brand(if anyone has done it)
Also, when a header is installed the first cat would be tossed (say like the MazdaSpeed header... yes/no?) or does the header have dual cat provisions?

Greddy917

I have a friend that does custom fabricated exhausts (he did mine-beautiful work) If any of you all are interested...we can fabricate a completely bolt-on strait pipe to replace the second cat....it would be fit up to the stock hangers and be flanged just like the stock secondary cat therefore connectable to any aftermarket exhaust. We can make it 2 inch or 2.25 inch or whatever you want.
Let me know if this is something you all would want for your cars...If so...I will find out what it would cost.