Anarchy_4play

The link orlando gave, that car has one cat. mine has duals.I'm trying a couple other different suppliers. i'm not going to pay over 300 a side. thanx for the suggestion crazy i still might go with a custom built exhaust.

CrazyCab

<center><img src="http://pictureposter.audiworld.com/76266/mvc-008f.jpg"></center><p>
the oxygen sensors. This should only be necessary for the sensors after the catalytic converter, as the two oxygen sensors b4 are mounted on the exhaust header b4 the downpipe.

Real quick, what year/model audi do you have.

In Orlando's link, that car originally had two cats, but when the aftermarket system was made the owner decided to only have one cat. This is completely viable on your end as well. Others here have done it b4 without any issues. Its all a matter of preference, when I had mine made I stayed with two cats (pic).


Cost wise mine ran $750 including parts and labor, but I spent $250 on cats and mufflers alone as I went with high performance. Labor was $500 but I also had the entire exhaust done from front to back.

If you decide to have the entire system done, make sure the middle muffler/resonator stays in place, removing it will cause the noist level to increase significantly.

Anarchy_4play

can you get aftermarket cats with bungs in them already? i'm planning on sticking with doing only the front for now.Do aftermarket resonators not silence the system enough?

CrazyCab

<center><img src="http://www.jegs.com/images/photos/600/642/642-53033.jpg"></center><p>
Jegs, Summit, etc.. all carry them. Here is a pic and a link. Google "Single Sensor Catalytic Converters " and you will come up with a lot of options. The only thing to double check is the stock size of the existing pipes, I don't remember whether 1-3/4 inches or 2 inches is the closest to the stock size pipe. Remember the stock pipe is in millimeters, so nothing will be a perfect fit, but the shop will be able to expand the diameter of the pipe if necessary.

And yes you are correct, aftermarket resonators don't do the trick regarding sound. But on a positive note, the stock resonator in your car is the best option and completely safe even if the car has added horsepower. It will keep the system quiet but it also will not hinder performance, so you get the best of both worlds.<ul><li><a href="http://www.jegs.com/p/Magnaflow/803583/10002/-1/10251">Single Sensor</a></li></ul>

Anarchy_4play

What size did you make your exhaust when you modifyed it?

CrazyCab

the two front pipes come together into a "Y" pipe, and from there on out mine is 2.5 inches

In your case, your only looking for the front portion so 2 inches should fit fine.

Anarchy_4play

Thanx.