Been through dozens of threads on this topic but still can't seem to find consensus regarding the right y-pipe.
Have an 05x and need a replacement y-pipe that will fit the AWD and mate to the stock mid-pipe and cats.
I see conflicting info on the threads about inlet and outlet sizes and if it clears the transfer case. Don't want to buy the OEM from Nissan at those prices. Would prefer a good quality aftermarket Y-pipe with perhaps enhanced sound that will match same dimensions as OEM.
The existing mid-pipe flange is badly rusted so my shop may need to weld a SS coupling to the outlet of the new Y-pipe and not use the new flange - that's ok because i may keep my old sedan mid-pipe for now. And i may get a HKS axleback too.

Just need links to a vendor or make that will work. Any suggestions?

 

Marinelli Motorsport is where I bought mine. I have an 04X. My setup for now is the Megan Racing Ypipe, stock midpipe and HKS Axleback. Its Awesome! future plans are to swap out mipipe for a coupe middy.

Think i paid somewhere of around 150 shipped.Hope this helps.

 

I think the M2 Y pipe is the one that works. Look into the shape of the Y.

 

How did you connect the new MR y pipe to the old mid pipe? The new y-pipe has a 3" outlet and the existing mid pipe inlet flange is about 2.5". Did you use a reducer coupling or just mate up the flanges somehow.?
I want to get the HKS axle back too. How is the sound compared to stock? Where did you buy the HKS and what did you pay? Did you get the OEM version - "sport"?

 

i have an 06X and i have a coupe mid pipe on mine ,i also used the OEM hangers as well... enjoy mate

 

So I just installed the MR HR y-pipe on my 05 G AWD. Because the outlet size of the new y-pipe is 3" (the original stock pipe has a 2.5" outlet), I bought and installed a 3" flange and a 3" x 2.5" cone reducer from Flowmaster. This cone reducer is about 6" long and is tapered. I did this to try to prevent rasp.
The parts were well installed at an exhaust shop. The shop welded the 2.5" end of the cone reducer to the existing sedan mid-pipe (2.5" dia). No exhaust leaks. Gaskets and flanges are tight. Y-pipe does not appear to contacting any heat shields or other parts.
BUT - now I have an annoying rattle/buzz. (Rasp??) when accelerating between 2800-3000 rpm. Noise is coming from the area of the y-pipe. Noise is a higher frequency metallic sound
Is this considered rasp?
Maybe the cone reducer isn't helping enough. Need to keep 3" diameter all the way back?
.
If so, should I replace the mid pipe and stock muffler with a 3" OD y-back system - resonator pipe and new muffler? I want quiet exhaust - no drone and no rasp. Any suggestions?

 

Do you have any pictures of your setup?

 

I know you said all the shields are tight, but have a look at the heat shields on the cats. They are prone to rusting, and then rattling because they are loose. My G has the same sound - if you're in Jersey, there's a good chance those shields are rusting. Years of salt and crap will rot the welds on the shields and exhaust flanges. Let us know what you find!

 

Fixer - you are right! Underside of my car is very rusty from the salt and snow of the Northeast. I removed the heat shields from the cats LAST year because they were rusted out and rattling.

I just replaced the original y-pipe a couple weeks ago because the heat shield and insulation jacketing and flex sections was rusted out and rattling. The new M2 HR y-pipe is stainless steel and has no heat shields. I am getting a new, different kind of rattle noise. It's more of a vibration buzz (rasp??) when accelerating and in the 2600-3000 rpm range. Engine has to be under some load. The exhaust tone with the new Y-pipe sounds really good out the tailpipe.
I have the original sedan mid-pipe and muffler. These too have lot of external rust but no perforations or leaks yet.
See attached photo of the new Flowmaster venturi cone reducer fitting i had just installed to mate the new y-pipe with it's 3" outlet to the existing 2.5" OD mid-pipe. The y-pipe is on the right, mid-pipe on left. I bought a new 3" flange too and the shop welded the flange to the 3" end of the reducer and then welded the 2.5" end to the midpipe after cutting away the old rusty flanges. I thought this arrangement would prevent the rasp because its a more gradual transition, but maybe this new noise is just still rasp!

 

here is photo of new cone reducer fitting between the new HR y-pipe outlet (on right side) and the old mid-pipe (on left side of photo). Note the new 3" flange and gasket mated to the 3" y-pipe flange.

 

If I were you I would just save up and get a full stillen exhaust

 

Yea, the vibration/rattle/buzz may be rasp after all It only happens during acceleration or engine load and only in the 2600-2800 rpm range. With the windows closed I really don't even hear it.
The next move will probably be a full 3" diameter size y-back exhaust setup like the Megan RS-OE. maybe this will get rid of rasp. But then I could get new drone instead. Nothing's perfect. But I will need to replace my rusty OEM muffler and mid pipe soon anyway, especially after this nasty winter and road salt!

 

It seems the rasp was reduced quite a bit by resetting the ECU and using 93 octane Sunoco. I tried some 87 octane just recently and the rasp came back. Is the rasp worth another $7 per tankful?? LOL
Still looking to replace the exhaust from the Y-pipe back with all 3" stuff and then a real Osrisis G tune.

 

you use 87 octane? im no guru but i know when i bought my 06x i read that the best to use for optimal performance is 93 octane. i accidentally filled up with 87 by accident, force of habit, and the car just felt sluggish. I had to let it completely run down to empty and get it all out and havent gone back to 87 since. if you value the life of your engine than yea i would say spend the extra $7

 

No reducer needed on mine. Go with M2 performance Y pipe, bolt straight to the cats, then I purchased megan mid pipe and exhaust.

I have an 06x and the Y pipe fit perfectly. I did the same searching as you and found this solution. I can only speak for the Y Pipe fitting the stock cats on the X though. Not sure about stock mid pipe bolting to aftermarket Y pipe. Good luck.