Ok, I've read some other threads about a rattling being heard at different RPM's. Mine is at 2200 RPM's and my first thought was the cat converter. Just got back from the shop and all the bolts were tight, and there is no cover for this converter. The converter is a new hi-flo stainless one. Anyways ..... the guy at the shop told me that the vibration was coming after the resonator and that the piping (piping from resonator to the muffler) is double walled. Is he correct? Is the piping on DC sport double walled? Another thing .... if the function of a resonator is to amplify vibrations then of course you'd hear it more after it than before it right? One thing for sure the rattling/buzzing is very annoying. Any help would be great.

Thanks

Rick

the resonator doesn't amplify vibrations, it quiets down the exhaust. Whether the piping is double walled i really have no idea, but if it is coming after your resonator, you sure it isn't the muffler itself rattling.

ok i thought it amplified, thanks. We were using a big ass screw driver to see where the vibrations were coming from and when we pushed on the pipe after the resonator @ the S curve the rattling quieted. This was before the muffler.

That's when the mechanic said it was double walled pipe and he could drill a hole in the pipe and spot weld the two pipes together at the location where they're vibrating. This would hold them together and stop the vibrations.

So if the vibrations/rattling are loudest after the resonator it wouldn't be upstream then? What do you think?

no it wouldn't most likely upstream. Where you hear it rattling will be where the rattling is coming from.

ok, if i get a confirmation that the DC pipes are doublewalled then I'll be 100% convinced of the location and have them spot weld it.

If anyone knows if DC Sport pipes are doublewalled please let us know.

which DC exhaust do you have? Just the regular one or the TCS?

4-2-1 stainless header then a single muffler exhaust system

not to sound like an a$$, but are you sure it isn't the heat sheild above the exhaust pipe at that s-bend that's rattling against the pipe? I know mine was doing that, and I just bent it back off the pipe and waalaa, no more rattle, and yeah my rattle was at about 1700. I'd double check that, because if you have him drill and weld the pipe, that will be the first rust hole in your exhaust. Also, I am almost positive that the piping on a dc sport exhaust is not double walled. Honestly I've never heard of that on any performance exhaust. I know some stock exhaust's have a heat shield the whole way around the piping all the way back, and that might have been wut the mechanic was thinking. Let me know how it turns out for ya.

just checked the site out and they have re-designed their exhaust line except the TCS, wonder when that happened lol. Anyhow, I didn't read anything about double wall piping. Some of the other sites said something about double wall tips, but thats it.

Im not exactly sure about whether or not the dc sports exhaust is double walled or no, but judging both from pictures of it and the fact that pretty much no aftermarket exhausts are double walled, I think it is safe to assume no. If you have a jack at the house, get under the car, unbolt it real quick and take a look.

Other sources for the rattle could be:
1. One of the mounting hangars is bent, and not providing enough clearance when the exhaust hits it harmonic frequency (probably 2200rpm in your case)
2. You might have a bad exhaust, as in, the welds from the factory inside the pipes are cracked.
3. Something might be loose inside the pipes

If you suspect #3, have the exhaust taken off and check the inside with a flashlight. (if it's not coverd in soot)

yea the heat shields was the second thing i checked after my cat converter. I can put my hand between the pipe and heat shields throughout the whole thing.

Yea mine is not the TCS one. It's the regular single canister.

When you heard the rattling, did it come from inside the exhaust or outside it?

<racingnut10>: it was inside the pipe. when I press a screwdriver on it firmly the noise surpressed.

I imagine the best way to pinpoint the problem is to get the car back on a lift or jackstands, have someone idle it at 2200 and get under it to investigate.

Is it brand new?

yea that's exactly what I did. like i said i've pinpoited it but it doesn't make sense.

almost 1 year old.

well, what i'm thinking right now is that maybe some of the fiberglass inside of the resonator may have came loose and is bouncing around in your pipes

hmmm .... if that was the case it should just blow out of the muffler.

if you have a complete crap hi-flo cat, then mayb a piece of fiberglass came lose, and managed to get lodged in the pipe. however if it's worth more than 2 cents then i'd rule that option out instantly

Did you check all the exhaust bolts?

There is one problem with the fiberglass coming loose. If the fiberglass is loose, then part of the baffle that keeps it in place and out of the main exhaust flow is loose.
Anyway, if you have the time, unbolt it and flash a light down it to see whats up.

ah yah, i forgot about that metal screen...

however, check ALL of your gaskets, from the header flange all the way back, you may have blown part of one out and sucked the rest in, and it's stuck there. doing as racingnut10 suggests and unbolt sections and check them w/ a light.

see anyone can forget things from time to time... GScivic7

...but if that is the problem, then the metal screen would be what is rattling...
All this still sounds like a least likely scenario

whether knowing how VTEC works or not and then claiming you know something about it when you don't know shit is different

Amen!!
Preach it Pastor!!

...but if that is the problem, then the metal screen would be what is rattling...
All this still sounds like a least likely scenario
i know, you really need to just take it apart.

dude i'm just giving u a hard time like u did me, i do know, but knowing and being able to explain to sumone else isn't the same thing. just cuz i'm new to the forum duzn't mean i'm new the technical crap. i'll admit u did know it more than i could explain it, and u called me on it, but it duzn't mean i didn't know it to begin w/. besides i wasn't explaining it for u, but whoever mentioned coolant as the fluid used.

go out and drive a little

Guys please.

Anyway, GScivic7 aqre you looking for HX wheels too?

nah, 15" nissan wheel covers without spending out the ass

hey, GScivic7, i'm offering a truce. we cool?

talked to DC Sports .... single walled piping.

Read some other info. Low octane / cheap gas causes engine noise, which could be amplified by the exhaust.

hmmm ..... i guess i need to burn that cheap ass gas up and run some amoco gold for a few tanks and see of that helps.

I'll keep you guys posted.