Spider-Man

Alright, I've replaced my muffler and my y-pipe with a WarpSpeed and my car is very loud and slow. I've got a 1996 Maxima GLE with 128,000 miles. Looking under the car, the noise is coming from the back side of the cat along with some steam at the joint between the cat and b-pipe. Is it possible that my cat is clogged? After installing the Warpspeed, my car has gotten slower. My guess is because the flex pipe was disconnected--the reason I replaced the y-pipe in the first place--allowing the exhaust to "by-pass" the cat. All of my connections are good with no signs of leaks. Do cats usually go bad around this mileage in Minnesota? The exhaust doesn't smell bad and it seems clear. Thanks.

After this, I'll fix my radiator support

carsnwomen91

Any check engine codes? I'd start from there

Zach-R

iTrader: (3)

Even if there's no codes check anyways, knock sensor might be bad.

D.Stillwell

What you described sounds very much like you have a leak in that connection. As a matter of fact, the B-Pipe to main CAT connection has been known to be quite a problem for many people, myself included.

The B-Pipe to CAT connection is known to rust, have seizing bolts, etc. That connection is known to have issues with coming apart.
That's why when I did my Y-Pipe I went ahead and put in a high flow CAT as well, not because I necessarily needed to or wanted to but because the old CAT was ****ed and wouldn't come apart from the B-Pipe without destroying it.

So my suggestion is that, I'd be almost 100% sure it's the B-Pipe to CAT connection you're having problems with, and since the car is noticeably slower, you're clearly losing quite a bit of pressure in your exhaust.
Must be a decent sized leak because a tiny leak wont make you feel much power loss and actually might feel a small gain.

You most likely have a bad CAT as well, probably clogged and rusted to boot so it's just making the problem worse cuz you've got residual exhaust gases sitting there but not enough pressure to push it out so you've just got all this left over exhaust sitting in your cylinders and all the way back down your exhaust system. And since you've seen a visual leak in that spot, yeah, that's not supposed to happen that way, if you have steam coming outta there that's your problem right there.

Now, for the loud part -- also a sign of a leak somewhere in the exhaust system. A warpspeed shouldn't be that loud and I've seen a ton of them since most 5th gens go with the warpspeed.
I have Cattman Ypipe myself w/ high flow cat and a new stock 5th gen muffler and my car is very loud at WOT but has a really nice high pitched sound at lower RPM, and the Cattman Y-Pipe adds a more deeper raspier tone too, sounds sort of like a V8 when idling after a cold start. Warpspeed YPipes are known to have more of a high pitched sound (Honda) and some people complain they sound too ricey, hence why I shelled out extra $$ for the Cattman (well worth it, better HP gain w/ equal length collectors). So perhaps, depending on what other mods you have, the loudness may just be normal. I know the Y-pipe by itself definitely made my car WAY louder than it was so perhaps your loud is normal (especially if you have Intake + any other exhaust mods) but the leak is pretty much definitely there right at that connection where you saw it.

EDIT: Noticed you also did muffler. If you put on a new stock 5th gen muffler like me, with a YPipe + Intake and other mods that will make it really loud high pitched growl for sure, also depends on what B-Pipe you have and what resonator/silencer you have, etc. Aftermarket mufflers are usually way louder plus have a way more high pitched tone.

Oh and last thing, Y-pipes are usually a good bit quieter when first installed and new, I've heard this from a bunch of people w/ Warpspeed and Cattman, but Warpspeed more so. Which means that thing should actually get a little louder after it's broken in. So if it's too loud for you now, that means you DEFINITELY have a leak in your system.

Spider-Man

I have a check engine light, but I figured it was the O2 sensors because of the flex pipe being disconnected. I should get that checked out. It's definitely loud, and it sounds like it's coming from the resonator/rear cat.