I've just installed my stillen y-pipe! I hear hitting/vibrating noise in 1st while accelerating. I have not fully investigated this. Looking for the quick fix! Has anyone experienced this?? Also, have r.t. cat and stillen cat back.

 

Check the bracket around the Y-pipe / Cat junction (the one with the rubber hangers). If it's too far to one side of the car it might be hitting the body. You should be able to bend it and then it won't hit anymore... at least that worked for me.

 

That is the general area of the noise. The bracket you are refering to, is it the one that holds the rubber hangers. as you already know with R.T. cat I no longer use the hangers. Do you believe there's that much lateral movement between flex sec. and the cat?

 

Also check the metal clamp on the B-pipe connecting to the muffler. That was banging on mine.

 

Yeah the bracket with the rubber hangers. There is only one bracket where the Cat and Y-pipe meet.

Why can't you use the hangers? Even with the RT cat the hangers are used at least with my RT cat and Y-pipe.

 

My cat doesn't have the little hanging nubs!

 

I think you are getting something confused.
The cat is bolted to the B-pipe in the back, and then bolted to the Y-pipe in the front.

The bracket that I'm refering too is in the front, where the cat and Y-pipe meet. This bracket is actually looped underneath the flange of the RT cat and the bolts go through it.
Look at this pic.

http://www.greghome.com/images/Maxim...oveCatNuts.jpg


If you look at the top of the bracket, near the rubber hangers on both sides, it might come in contact with the body of the car. This is what you have to bend.

 

This bracket is no longer existing on my car, it came off all at once with the rest of the stock exhaust. Then was replaced with an R.T. cat and y-pipe

 

umm.. just to inform you man.. the r.t. cat is not suppose to replace that bracket.. your suppose to take it off and reuse it.. your better off buying a new one, its about 35 bucks from nissan. i have the exact same exhaust as you, and something is also hitting in that area( along with the two other places it was ratteling),some im not so sure its the bracket thats hitting, but you really should put it back to take the stress off the flex section.

 

I have the same setup and would have to agree with KC. I reused that bracket.

 

Generally I do my own mods! I decided to have the midas guys to do this ($57). I've also came to the conclusion that it was supposed to be replaced (thanks to breaux124's pic)! I just put one on order. I guess thats what happens when you don't do it yourself. Thanks for the post!