I need some advice! I just put headers on my 2001 accord. Im getting a buzzing sound during hard acceleration. I checked for leaks,and have found none. I bought all new gaskets,and used gasket sealer,but still no luck. I have replaced the headers with a 4-2-1,and the muffler,but not the catalytic converter. Could this be the problem? Do I need to replace the factory with a high flow? Also,there was no gasket in the flange where the headers bolt to the converter. Should there be one? All I could find was a donut type one,and all it did was create a large gap in the flange and leaked badly. I took it out,used some sealer,but like I said,no gasket! I can't seem to find out if there should be something there or not. With the flanges bolted directly together though,there is no leaking. No matter what I do though,I can't get that buzzing sound to even change,let alone go away! Very annoying! Sound a bit like it's got a turbo in it!

 

I don't know if your problem is caused by the muffler. But once I bought just muffler shop muffler (nothing else) and it made my whole car vibrate. It sounded like my engine was coming apart. That was until the inside of the muffler fell apart, then it was just loud. Finally got another Honda muffler, and it was llike a new car again. I think some mufflers make just enough back pressure to cause vibration. Just a guess, I'm not an exhaust pro.

 

what kind of muffler do you have? Did you do the muffler install yourself? If not, where did you get it done (I'm from orlando also and I got my done at Ice Cold Auto/Muffler city up on colonial, had same problem).

 

It could just be leaking from the head maybe behind one of the runners so it's hard to see.Try torquing the bolts again and see if it helps.
Sometimes if its not a quality header they just weld the runners onto the flange and that causes it to warp a little bit making it leak between the header and the head.

They are supposed to weld the runner on then grind the flange flat again.

 

It's a cheap ebay muffler that I put on myself. The noise seems to be coming from the front more than the back.With the hood up,car running,if I rev it from under the hood,you can hardly hear the noise at all. Once you drive and get on it a bit,this squeeking/whining noise can be heard. Sounds like it's coming from right under the middle of the car. That's why I thought it was the converter.I did re torque the bolts and bought a new $15 gasket to replace the $5 gasket on the manifold. I even tried doubling them too! No matter what I do though,that damn noise won't even change the least bit. If it would,then I could narrow it to a certain location on the car after I mess with something.

 

You may be the victim of a broken heat shield somewhere along the exhaust system.
I'd first look at both the upper AND lower heat shields which are welded to the Catalytic Converter case. These welds are prone to breaking, allowing the shield to "BUZZ" at certain RPM ranges. On the 5th Gens' it was from 1900 to 2100 rpm; and you would have sworn something was about to do some real nasties.
Have a close look.

P

 

I need to look into that also, I get random buzzing (althought I think it was the plastic connectors in my car).

Same problem with me, I've got a resonator and the silencers in, but on the inside of my car at 2000-3000rpm things like to buzz or shake but it goes away when I'm over that. It's only in slow acceleration like if I'm idling down the highway and hit the gas harder to get from 2100 rpms to 3000 to speed up somewhat. I'll check under the car in the morning.

 

The crack in the shields is a very good possibility. I will check that out.Thanks! That's along the lines of what I was thinking. Im figuring that withe skipping the converter when doing my exhaust,it's now creating the exhaust flow to bottleneck at the converter,thus air is getting squeezed out somewhere. If I could only find a way to climb under my car while doing 55,I could check it out! Let me know if any of you's have a nifty technique for that one!