Hi all,
I bought my Evo 1 month ago and want to change the stock exhaust.I'm a newbie and I have some questions:I would like to change the cat back,is there something special to change (I mean any sensor or something like this)? Well,I would like to buy the 5Zigen Miracle.If I change the intermediate pipe as well,is there a sensor to change????
Thanks.

 

Intermediate pipe? You mean the pipe between cat and muffler? If so, there is an O2 sensor in that mid pipe that needs to be removed and reinstalled in the new exhaust. That mid pipe comes after the cat so it will be included with the catback you buy. You can do the install yourself on jack stands and an impact wrench (I couldn't get the bolts on the cat off wihtout one).

 

Well, I had a look and took some picture under my car yesterday and saw how the exhaust line is made. There are 4 parts:
*the 1st one is the cat just after the turbo (downpipe isn’t it?)
*2nd one is just a cat with a sensor
*then 3rd is the intermediate pipe with a small black cat (I didn’t see any sensor on that one)
*and finally the 4th one is the cat back.
My question is when I buy a catback (for example the 5Zigen one),what is included? I mean there is only the catback and that’s it or the ‘’intermediate pipe’’ (I don’t even know if it’s the name of this part) is included as well?
To gain horsepower, which part do I have to change?
And finally, concerning the second part, is it possible to change it and to put again the stock sensor on a aftermarket one without any check engine alert or other problem?
Thanks all.

 

Full turbo back ex, from UR racing, had the setup, fit and form flawless, had cat delete, no ecu probs. My money is there, but you can do just aswell with many others.

 

So you mean the best way to gain horsepower is to delete the second cat and to change the catback?

 

Cikay,

The best hp gain is to go with a turboback exhaust system (3", mandrel bent).
This includes the downpipe, test pipe/cat delete pipe, and catback.
Basically this replaces the exhaust work from the turbo all the way back through your exhaust tip.

When you buy a catback, this should include the midpipe and the muffler/exhaust pipe. Catback means exactly that, everything from the catalytic converter back out to the exhaust tip.

Usually the biggest concern for a CEL comes from changing out the cat and replacing it with a test pipe. This usually can be alleviated by an 02 simulator or a sensor relocation.

If you're interested, I have some pics I can post/send later that are sitting on my digital camera of each exhaust component.

 

Dude - the exhaust from the tubo back to the exhaust tip is comprised of the downpipe, catalytic converter, intermediate pipe (or midpipe) and the axel back (including muffler) - essentially 4 pieces.

the "2nd" catalytic converter you refer to is actually the resonator in the IP (intermediate pipe)

Most people would agree that the most restrictive part of the exhaust is the AB (axel back) which contains the muffler. the stock muffler has a spring loaded gate which is quite restrictive. If you're not going to do a full turbo back, I'd change this first. The 2nd most restrictive part is the downpipe. The stock IP is actually pretty good. It is the least restrictive part of the stock exhaust.

good luck

 

Hi,

for sure I want,send me the pictures please.So if I understood,to begin the most interesting thing is to change the cat back (muffler+internediate pipe) and then to change downpipe.

 

Hi,

does the new Perrin downpipe in 3 inch fit with the stock mid pipe etc...?

 

Hi all,
I don't know if in Europe we have the same exhaust system.Here are the pictures I took from mine:

 

From those pics, it looks like you have a cat converter in the downpipe? So that is different. The US dpwnpipe doesn't have that. Other than that, they look similar. From your second cat back, it looks the same as the US spec. The bumps in the mid pipe are resonators, which we have as well.

The cat backs include the mid pipe and bolt to your second cat.

Axle back systems retain the mid pipe and just change the last pipe/muffler.

 

Hi,

on US Evo downpipe,is there any sensor? Cause it seems that there is nothing on my downpipe cat! Just to know if it's possible to put a aftermarket downpipe without any cat.And when you say catback system include muffler+mid pipe,you mean the pipe with the resonator?
Thanks.

 

Yes, it is possible to use an aftermarket DP w/o a cat - its called a cat delete pipe, and leads to heavy fines (in the US) if you get caught w/o it. Many vendors offer these. A high flow cat is another option.

A catback system refers to the exhaust parts downstream of the catalytic converter - the IP (intermediate pipe (also called the midpipe)) and the AB (axel back, or part with the muffler). the pipe with the resonator is the IP.

 

OK thanks.So what i'm going to look for is a downpipe (cat delete) nd a catback.