I have a 2004 gt and would like to know where my air silencer is located so that I can take it off.
I think I know where it is but not sure.
Is it just the cover around my intake?
will it make my car sound louder if i take it off?

 

No, the cover around the air filter is the air box... the airsilencer is a little rubber extension to that, which points into the fender-well.

You don't need either of them, but I think it's advisable to keep both. The air silencer actually does pull part of its air from the colder fender well... by removing it, you are more likely to get hot air from the engine bay.

Same goes for the airbox, it shields the filter, and when used with the air silencer, it helps to pull air from the fender, instead of the engine bay. You can remove it, but you will be getting pretty much exclusively hot air from the engine bay (much like a K&N FIPK).

The difference is immeasureable no matter what you do.

 

this should help:
https://mustangforums.com/m_1135032/tm.htm