I can't figure out why my exhast is making this weird buzzing noise. When I'm driving and I punch the gas, I get the sound. If I let it rev all the way up, the sound disappers around 3800 rpm and comes back at about 5200 rpm. It happens a lot more when the engine is cold. I have I/H/E and a high-flow cat (basically just a straight through resonator). Does anyone have any suggestions? The only thing I can think of is my cheap muffler (magna-flow).

maybe you need a gasket

Sounds like a loose weld to me. I had the same problem in my CRX and it was a broken weld around my resonator.

Graydon

you might also want to check that it's not rattling off the heat sheild.. when ya first start it up it'll shake a bit and by some off chance it might be hittin it somewhere..

True that. My A'pexi WS system I got recently seems to be vibrating up on I think it's the hangers when I'm stopped at a light, or just sitting at idle. :(

I'm sure it has something to do with the actual exhast flow and not a loose rattling. Is it possible that it's my exhast (header) gasket? If not, I can only think of two other places where the actual exhast system can be taken apart - before and after the high flow cat. Now that I think of it though, I think the sound first started when I got my header. Is it possible that a damaged header gasket would cause this kind of sound?

its just resonance. sounds like its farting huh? yeah, lots of cars have this problem with aftermarket exhaust. what you need to do is buy a resonator and it will take out the noise.

I had a resonator, but I took it out. :bloated: As soon as I did, it was a lot more responcive. It sounds more like hockey cards taped to the forks of a bicycle so that they flap against the spokes. Like something is rattling back and forth against the inside of the exhast. If this is resonance, will a different muffler solve the problem (I don't want a resonator)?

Do you still have your cat? or a test pipe?
Mine does the same thing and it started when i put a test pipe in it.

i think it's your exhaust. my friend has a magnaflow on his integra and the thing sounds like crap it sounds just like baseball cards attached to the rims of a bike. i know another kid that has one on his 89 accord, but it doesnt sound that bad now that i think about it... you aren't running your stock pipes up to the muffler are you?

Nope, 1 1/4 or 1 1/2. I can't remember. It's just mandrel bend exhast shop tubing.

I have a high-flow cat. It is competely straight through. So yeah I guess it is a test pipe with little holes on the inside. I think mine started making the sound when I took out the resonator that I had the exhast shop put in the piping. Now I'm thinking it's just the damn magnaflow muffler.