weird noise from cat back

wasup everyone..i just installed a tsudo cat on my 99gsr back last week..everythings been fine except everytime i start up the car..as i go and come to stops..my exhaust would make weird rattling noises.not only rattling but then weird noises.i cant really describe it.but as i continue to drive and warm it up..it seems to go away later on..

i was wondering what it could be? any help..

if you unbolted/unscrewed the metal cover on the cat, you could have left it loose and it would rattle.

do u have the silencer in? because tsudo is known for not having a well-fitting silencer included, and i know when mine was in, it rattled like a mofo.

i'd check that first, most def...

I know exactly what it is(I think) I had the same noise your talking about which is very hard to describe. Your missing and or have a high flow resonator and when you don't have a resonator the muffler will vibrate until the car heats up and then go away once the car is warm. All i did to remedy this is put an exhaust tip with a resonator in it and voila, no more noise or its so very minamal its not noticeable. I could have this all wrong but I think I've somewhat got it. And it might be kinda hard to swap out tips if you have a muffler with one built in. I bought a turbo muffler from summit racing so my exhaust system would look stock. :iceslolan

thanks for all the replies everyone..you might be right about the reasonator/silencer..because at the current moment i do have it in..but then i want it in so it will continue making the noise..is there anything to do to the silencer to make it go away with it in because without it..its way too loud.

hey im sure now that it isnt the silencer thats making the noise..every single time i start the car it makes the noise and then goes away..as i start to drive it appears to be coming from under my car somewhere along the middle of the catback im thinking maybe its not bolted tight enough and it can be loose?.but it was done tight...its just rattling from under the car and im sure its the catback just cant figure out what and which part..i would be at a stop and rev to about 2 rpm and as it decelerated on its own around 1 and half it makes the noise..and thats everytime..help please..

I would definately get under the car and see if that bad boy is secured under the car.

ok i believe i got the answer ur looking for :icon16:.does it sounds like something is rattling when ur driving and and stops making that noise when your car is at a stand still? and can u give me any more details since i think i know whats wrong, but i wanna make sure.

it makes a rattling noise in low rpm as i decelerate rpm..and its coming from the the middle of the car somewhere along the middle of the catback..i gas it to 2 then let go and around 1 n half it makes the noise and stops after that..and everytime i start the engine it makes the rattle until i drive for about 5 minutes

ok heres what im thinking since it is happening to me also. first of all the cat back you got is a bolt on, but the problem is that it's not the exact shape as the oem. under your car, but above your exhaust system is a kind of metal guard, do u know what im talking about? since your exhaust has similar angles as the oem but not exactly the same it is causing somewhere down there to rub against the metal guard. like when you do start up your car, it vibrates more until it's warmed-up and when in motion your car will also vibrates causing the exhaust to rub. my suggestion would be to look thoroughly for scrapes on the guard and either push it farther away from the exhaust or remove the guard completely. this shoud help. i have the same problem and will finally have time to fix it tommorrow, since im going to do and oil change.

i got the same problum, and what the guy before me said is exactly the problum, im ganna get under my car today and see whats up, its really annoying getting our of school and everyones lookin at your ride like its screwed lol. ill keep yall updated on how to fix it, is there any draw back from taking the top metal part off? i think it might be there for reducing the noise inside the cabin. i wouln't mind it getting louder because magnaflow exhaust are really nice sounding but i wanna hear it alittle inside too.

i just got back from fixing the problem. It is the metal cover over and cat and the s pipe. It touches the s pipe at the very end and to fix it Honda has made 2 hangers at each location so you can adjust the height of the exhaust but not by much. the problem is fixed and another thing you might want to do is try to bend the shield back because i was going a 110 and on a slight curve the noise came back but then went away. it never came up again after that thankfully.

tell me if it works for you and how you fixed the problem.

that makes 1 down and 2 rattles to go and since were on the noise subject i wanted to see if you all could help me.

1.theres some noise coming from dust shield right above the header when the engine revs from 35000-4000 rpm i cant find were exactly its rattling but when the engine is warmed up the rattle goes away for the most part. do you no how to fix this or if i get DC 4-1 header will this eliminate the problem?

2. my hatchback/truck makes a squeaking noise and i hit little pumps. Iv tried greasing it but it never helps. if you all could help in any of these areas it would help a lot thanks.

theres a way to tighten up ur hatch and its fairly simple....my friend was tellin me the other day how to do it but i wasnt payin much attention....ill find out from him soona and post on this site again the remedy

ok i finally fix that rattling on my teg. yesterday my friend did the oil change and i search for the noise problem. noticing some scratches on the last metal plate which turns toward the muffler, i removed that out. when finally done we test drove it to get something to eat and still heard the rattling although this time it wasn't as loud and distinct. today i went back under and search for it again. having my teg on top of jack stands, my sister pressing on the gas, and i next to the car listening (not underneath, that plains stupid), had discovered it was coming from my cat shield. the company who i purchased the cat from welded the shield to the cat in several spots mostly in the middle but didn't weld it at the edges, thus causing it to vibrate making that annoying rattle. what i did then instead of removing it since that shield is important was using some pliers, i twist the edge of the shield upward so it doesn't touch the cat on either sides. when finished i brought the car down and test drove it again, this time no noise :smokin: . now i can call it a day.

the so called metal plate/metal guard..the things thats on top of the s pipe is what the pipes touching to make the sound..it seems to be bolted on..would it be safe and okay if i completely removed it..? that metal piece that is.

i removed only the last plate since that was the problem and didn't want to removed the whole thing since the guard was made for a reason. have u checked your cat shield? that could also be the problem.