So right now. I have a M2 cat-back exhaust and i am wanting to install a magnaflow y-pipe before the cat. I'm also planning on installing a magnaflow hi-flow cat as well. Does anyone know how much it shud cost to get that done?

 

well it should be just bolt on and alittle spot welding.
shouldnt be that much
for *****s and giggles lets just saying 100-200?!
someone correct me if im wrong.

 

Will this give my car a deeper sound? Will it be louder?

 

The M2 exhaust is already deep because of its 3'' piping. If you want it louder get rid of your resonators and cats.

 

If u install before the won't u through a code?. Don't u mean after?

Top speed pro y-pipe installed. Ill post a pic when my internet is back up.

The sound is perfect for me while still retaining smaller resonators.

 

the M2 exhaust came as a cat-back setup. so i have two of the resonators deleted. im looking to extend my exhaust further back.

 

Further up...

I'd be concentrating on getting headers. They will change the sound entirely and actually make some power.

 

Just remove he resinator on the mid-pipe. This will make it louder and it won't mess with your O2 sensors.

 

Cud I get headers and still keep those stock pipes, in between the headers and the cat??

 

Yes.. i believe so... It should be a direct fit... Finding headers is the hard part

 

I was taught that if ur doing exhaust that u start from the back and work ur way up....correct me if I'm wrong

 

i'm not really sure bro... Maybe 99GS3 can chime in or Jbrady.. I think your setup is loud enough to be honest.. Mine sounds pretty good but not as loud as yours since i still have resonators only smaller.. I wonder if a small X-pipe in place of the third muffler will throw a code? Hmmm