I have just replaced the exhaust system. I bought it from a friend and instead of three catalytic converters it now has one. They said it would not change a thing.However now there is an annoying buzz sound coming from under the car . It almost sounds as if there is an exhaust leak. I was looking at Racing beat and they have a presilencer which looks as if that would be the way to go to kill the sound. Could it be my answer? Will it fit a stock exhaust system ? Is there another answer to this situation?

 

does the cat have an air pipe on it?did you remember to hook it up?is it in the vicinity of the cat?did you check the head shield?..stuff to ponder..

 

HEAT shield ..sorry

 

Your details are horrible:


What did you replace?
With what did you replace it?
Did you do the work?
Did all the components fit right?
Did all the gaskets look in good condition?
Did you tighten the hardware properly?

 

A. I replaced the exhaust system from downpipe to mufflers.
B. Stock parts
C. No, I had a local shop that specializes in rotaries install it
D. Yes, they actually commented on how well the parts went on, and how
difficult the old came off.
E. The gaskets were all new and they looked good before the install
F. I would assume that the shop tightened everything properly

 

The car does have a cat on it and it feels and looks as if the air pipe is secure.

 

I really don't understand the problem here. To find out if the car has exhaust leaks, just look. If something sounds like it's making noise, you would know what it could be more then any of us, as you were just in there. Certainly you looked around at what you just worked on and could come up with possible causes the "BUZZ"

Any SS packed per-silencer of the proper diameter will work. No need to pay more then you need too.

 

If you have an exhaust leak, identify and make your installer fix it.

If you have a rattle, you can often find it by lifting the car (easy to do this at the installer's garage) and lightly tap on the system in several places with the palm of your hand. DON'T bang on the converter!!! This will make the system vibrate and will often make the location of teh rattle or buzz apparent. If something is loose, they can fix it. Sometimes a system will simply ring with a buzz. A good exhaust shop will be able to adjust the hangers a little and adjust the resonance out.

If you are talking about a raspy exhaust note, add a presilencer ahead or behind the catalytic converter. Rotaries tend to sound raspy, but I don't know if this is what you are referring to.

Good Luck