CARSNBIKES

I have had my GS since october of 2013 and I am now looking to free up the exhaust and I am running into some issues figuring out what to do. I have fooled around with removing the mufflers, tried removing the Y pipe, but the bolts were too rusted and were going to round. So in good spirits I took the system off right after the catalytic converter to see what it would sound like. Needless to say it's been about a week and my ears are still ringing. I have a few questions about the exhaust system and anyone with experience modifying the systems or doing custom systems for it.
1) In between the Y pipe and Cat there is a component on the curved section of pipe shrouded in a metal cover. Is that ANOTHER muffler/resonator?
2) If you have had any custom systems made for the car could you explain what you had built and post a sound clip/video?
3) If you have a kit could you link me to where I might find it and also post a sound clip/video?

I appreciate any help!

CARSNBIKES

This is the component I was asking about!

Nixspeed

That is a cat. I made a full custom exhaust. Very quiet but not cheap.

CARSNBIKES

If that were a cat there would be an o2 sensor after it. and the cat is before this. cats have an o2 sensor befor and after them to measure effectiveness, there is no o2 sensor after that component.

CARSNBIKES

http://www.partsgeek.com/gbproducts/...uYQaAj1m8P8HAQ
this is a link to a direct fit cat for our car. If you see the split intake pipes it should make more sense, we have two exhaust pipes exiting the exhaust side of the engine, and those are the two inlets for the cat. At the end of the line it hooks up to only one pipe, and that's the rear end of the car where there is one more o2 sensor.

Nixspeed

Only the primary cat on obd2 cars have pre and post o2 sensor. Almost all the cars from the 90s on have a backup cat. I've been building custom exhausts for 17 years as well as building race cars that entire time. Believe what you want.

CARSNBIKES

I stand corrected, later after that I finally got those bolts loose and was able to look down the pipe to see the cat. You were right and I apologize for being misinformed, as it goes that is in fact a part to learning. I had never had any experience with with catalytic converters not having pre/post sensors. I have since spoken with three custom shops and my family mechanic to discover a lot about how I could get a better sound from the car and free up the exhaust. With your experience, can you offer an opinion about a cat-back dual exit exhaust starting after the primary cat and eliminating the secondary cat.

Nixspeed

It can be done. It'd be best to y it into a single 2.5" pipe until you get to the rear axle then split it again. Basically copy the factory design with smoother bends and slightly larger pipe. Don't go over 2.5" if you plan on sticking with non turbo.

CARSNBIKES

I do plan on going turbo later on, and most likely will try to run catless as well. Why do you say not to pass 2.5 Inches for N/A? i guess i dont understand what that would accomplish.

Nixspeed

For starters 3" is hard to fit so it hangs down a bit so if you lower your car a lot it'll scrape and damage the exhaust. Also 3" is to big and actually hurts your power. Now if you plan on turbo later you can do 3" and just keep a section of 2.5" up close to the motor so you can keep your power and have a good upgrade for later.

CARSNBIKES

Presumably the 3" section dials back the power because the air can move more unpredictably and not quickly away from the pipe?