I have a 07 GT with the modular x pipe, right now I have the cats on. Was wondering if anyone has heard it with or without them and the comparison?

Also what will be the sideeffects from doing this? Is it going to stink?

 

Only way you will know if you like the sound or not is to try it. Sound is so hard to describe, you have to hear it in person to know if you like it or not. And yes...it will probably stink....at least a little. But I kind of like that raw gas smell.

 

Search around for my thread "Borla vs Corsa" (or vice-versa) there are plenty of vids in that thread with the cats in and the cats out.

I liked it best with the cats in because with them out, the car trumpeted noticeably at 2500 rpm. If you don't know what trumpeting is, it's probably described in that same thread too.

 

I used to have high flow cats with my Bassani x-pipe. I recently swapped them for O/R pipes and like it better. The only negative side is that it trumpets like Tom said, Its raspy above 3500 rpm, and the raw gas smell is enough to make your eyes water at a stop . Other than that I think it sounds great, maybe some resonators and it will be perfect. I just made a soundclip with O/R pipes and Stinger A/B's but the sound quality is terrible and im having trouble getting it to play with windows media player .

 

Even though it's not PC, I love the 'raw gas' smell. It smells like muscle car to me.