I see a ton of dyno and faq about the y-pipe gains over stock, im just wondering if it will still give me gains with the stock cat-back.

Also how will it sound?

I want quiet so im am not getting a catback, i am thining about getting a y-pipe tho...

 

Yes it will. Ypipe will make it slighter louder inside the car, but with the stock catback it wont be much louder.

 

Having a Y-pipe with a stock cat-back is just fine, doesn't diminish the gains at all.

 

sweet, that's what i want to hear.

 

Yeah I have a cattman Y pipe with stock catback and it is really quiet. And it still gives you the power.

 

yeap

The catback actually does not give you much at all.

 

.

 

I put my y-pipe on as my very first mod and it isn't loud at all with the stock cat-back. I noticed gains right away. The intake I added is much louder.

 

I deliberated for some time about the Y-pipe noise issue as I didn't want more noise.
I bought a Budget Y-pipe and K&N panel air filter, no intake. Absolutely no difference in noise level at idle or crusing, but a bit of a growl when you are at WOT, which I don't mind at all. Because two pre-cats are eliminated on a 4th Gen the car will sound somewhat louder if you stand outside the vehicle when it is warming up. Make sure the car is good and warm when you go through any environmental test.