That's the same area I was having problems.

I just got my JIC y-pipe today. I'm going to install it this Wednesday. It seems to have a lot of flex (with mild pressure the y portion acts like a spring). For now I'm going to put my stock cats in until I know that the problem is fixed... I'm trying to isolate the variables. I'm keeping my fingers crossed that by midweek my crappy exhaust problems will be over.

 

good luck. Hope everything works out.

 

*UPDATE*

I found some extra time and was able to do the install today. The Nismo y-pipe was obviously toast ... when I pulled it off the drivers side wobbled around like jello when I moved it. Haha.

The install went quickly. I did a test fit and found that my test pipes actually fit well with the new y-pipe. There doesn't seem to be any stress anywhere. I loosened the test pipes and progressively tightened everything down. After starting it up I discovered a leak where the y-pipe meets the mid pipe. I re torqued and discovered the gasket wasn't that great (the new one from JIC)... I replaced it with the old Nismo gasket, and poof... problem solved.

So far everything sounds good. I'm still running the same test pipes. The sound changed some. The rattle/leak is gone. I do have a slightly noise under deceleration, but it sounds like my lack of back pressure. It took a little of the 'rice' out of my extremely loud exhaust and mellowed it out a tad. Still decently loud... just not as much sting.I'm going to keep my eyes on things.

I have a couple pictures to post to... I'm going to try to snap off a few more of my busted Nismo y-pipe

/novel

 

sweet that you fixed the problem. I'll stick around and wait for the pics.

 

Alright... here's a few pics I snapped of quickly yesterday. They're not the greatest but they give you an idea.

JIC: Left side, Nismo: Right side




My broken Nismo y-pipe... this is the expansion joint that went out and rattled/leaked like crazy.




You can see the discoloration in this picture from the exhaust leak. The problem started after only a day. The exhaust has only been on a 2-3 weeks. The sections of the pipe that run parallel vibrated extremely at certain rpms moving at least 1/2 inch.




Closeup during the original test fit between the test pipes and y-pipe on the drivers side. The bolts are obviously not tightened yet.



Also on a follow up note I got to drive the car a bit more today, and it sounds really good. Even with the test pipes in, it's quieted down a lot. There is no more drone noise on the freeway too which is nice for the commute to work. It still gets loud when you want it to... the climb over 3000 rpms sounds oh so good. Less rasp, and a little deeper tone. I would recommend this setup to others (assuming I don't have future issues).

 

I'm glad that you resolved your problem
Yea JIC tends to quieten down exhaust noise a bit.

 

Thanks again for the help and suggestion.

Also thanks to everyone else who helped out as well.

 

I also have the nismo exhaust on my 03. I had a pair of custom test pipes made out of a exhaust shop in des moines, ia. After about a week it snapped the drivers side of the Y pipe. I had him custom make that side and reweld the good piece of the y pipe with it. This made the car sound amazing. No rattles and way better then the nismo exhaust with the test pipes. Must have been the difference when he rebent a new piece of pipe for the drivers side portion of the nismo y pipe. The test pipes I had him make are just straight 2.5" pipe with my sensor installed. Brackets with rubber bushings to help with expansion when the motor moves to prevent braking. The system sounds amazing and looks great. The only other issue I have had is some dumb driver pulled right in front of my one day so I slambed on my brakes and pulled the hanger right out of the TP on the drivers side. Not a happy camper, rewelded the next day and it was fine. This is when we installed more rubber bushings at the hanger to hopefully prevent this in the future.