I bought my 07 G35x sedan w/107k about a month ago, The other day I started to hear some exhaust noise that seems to be around where the right cat meets the Y pipe. When I was underneath at the shop recently, I noticed it was rather rusty and the converter shields were barely on(they've since started rattling). The resonators and mufflers looked pretty sound.

I dropped it off today at I a shop that I do work for to be looked at Monday. Hopefully it's just the gasket between the cat and Y. If it needs a Y, they will probably offer a Walker replacement or similar, same for the cat(s). Most cars I've owned I would be happy for an excuse for a cat back, but I'm getting a little old for noise and these cars sound pretty good stock.

I've seen some Y pipes on eBay and other places that are supposed to be "high performance", and for less than I could get the parts store equivalent. Same for converters. Would either be worth bothering with since while I always welcome extra HP, I really don't plan on going any further mod wise?

If I did choose a new cat back, are any known to quietest, or close to stock?

 

I think the stock Y has a flex section--up north, those always seem to rust out eventually.

 

Mikeb33, sounds like your shop will take care of what your exhaust systems needs. You have the option of buying a new y-pipe or whatever you need from our Marketplace under vendor exhaust. Aftermarket y-pipes won't change the sound of your exhaust noticeably. I'm older than you and still love the crackle of a sweet exhaust...Gary

 

The flex pipes wear out badly. I put a Megan Racing HR pipe on mine, bought a used mid pipe, and had that welded to the muffler. Cost me about 500 bucks after all said and done. I needed another midpipe since the flanges were so shot.

You can put some seafoam on your car and see where it leaks. That's how I tracked my exhaust leaks down.