My car has done the same thing since I got it 30k miles ago... a buzzing sound from the exhaust when I gas it. Unless the sound bothers you, I wouldn't really worry about it.

 

I think I know the buzzing you are talking about. Check the heat shield for the cat. Sometimes these get loose and make a rattling sound under acceleration (~3.5-4k rpm's).

 

^^ Reason why I said make sure its the muffler. You say its really loud? Might also be an exhaust leak... I'm sure the stock pipes degrade if subjected to harsh elements pretty fast.

 

hmmm.. im not sure about the warrenty, im the 2nd owner and it has 56k... so it SHOULD have the powertrain.. also know about that recall/notice about the exhaust leak that most of us have gotten. i got one but it was for my 1st tib (RIP). so before i replace anything, i guess i better call the dealer..

thanks for all the feedback and ideas

 

I was thinking the exhaust leak as well. Is it for sure a buzzing or more like a hissing on the verge of becoming a buzz. I have a bad flexpipe. (that little wire mesh looking thing on your exhuast under the front seats) Check that to see if it's cracked or broken or something. Might be the cause of the noise.

 

Sometimes when muffler (catalytic or resonator) is old and internals of muffler (catalytic or resonator) did rust - it could produce buzzing sound.

To check this bang on muffler (or cat or res.) with your fist (be sure it's not hot). If you hear something moving or making noise inside - it's time to buy new one.

 

<div class='quotetop'>QUOTE (silvertibbs)</div><div class='quotemain'>I was thinking the exhaust leak as well. Is it for sure a buzzing or more like a hissing on the verge of becoming a buzz. I have a bad flexpipe. (that little wire mesh looking thing on your exhuast under the front seats) Check that to see if it's cracked or broken or something. Might be the cause of the noise.</div>

I was thinking flexpipe as well; I had to replace mine last summer for a similar buzzing noise. If it ends up being the flexpipe let me know b/c I bought a full after market exhaust and have no use for the stock exhaust and brand new flexpipe (about a month old).

 

so its the flexpipe that has the 3 X's on it thats written in white pen. (like i said before im not really an "under the car" kinda guy so please bear with me) im thinking the 1st owner got it checked out but didnt fix the problem. so if it is the flexpipe, i pretty much have to replace the whole cat huh? well ima get it check out, but if i do need a new cat, im sure plenty of you guys have ur stock ones sitting around.

 

If you get under your car again, look at the exhaust. The header comes from the engine then goes into the catalytic (sp??) converter, then from there it goes though the flexpipe, then out through the muffler.

There could be another cat on there after the flexpipe but I think that is only west coast tibs.

As for the flexpipe it is easy to pick out. It is steel weave and is the only thing like it on the exhuast. Feel it (when car is cooled down) to see if there are any breaks or rough spots on it. Be careful cause I cut myself on mine.

 

yeah i have a cat converter after the flexpipe... i'll get out there again after it stops raining (damn LA area!). from what i can see under the car is the flexpipe, then cat converter, then this thick piece of piping then goes to the exhaust then the muffler. the noise is so damn annoying! its even louder then i down shift for engine brake. BUZZZZZZZZZZZZZZZZZ! the only time it stops is when im at idle or not gassing it.