Removing your muffler
From the US EPA Noise Control Act of 1972, revised Feb, 1998. It's also in your Owners Manual:
"The removal or rendering inoperative by any person, other than for purposes of maintenance, repair, or replacement, of any of any noise control device or element of design incorporated into any product in compliance with regulations under section 4905 of this title, prior to its sale or delivery to the ultimate purchaser or while it is in use, or (B) the use of a product after such device or element of design has been removed or rendered inoperative by any person is illegal.
Criminal penalties
(1) Any person who willfully or knowingly violates paragraph (1), (3), (5), or (6) of subsection (a) of section 4905 of this title shall be punished by a fine of not more than $25,000 per day of violation, or by imprisonment for not more than one year, or by both. If the conviction is for a violation committed after a first conviction of such person under this subsection, punishment shall be by a fine of not more than $50,000 per day of violation, or by imprisonment for not more than two years, or by both. "
If you want to read the entire law here it is
http://www.netvista.net/~hpb/nca1972a.html
It is rare for inspectors to look, I wouldn't worry but you are still taking a chance in removing your muffler or cat. Most times all that will happen is a fix it ticket if you are caught.
You don't need an inspector, a regular cop could bust you if he has a mind to. Some folks have said here that a turbo qualifies as a noise control device and that you don't need a muffler, they are wrong.
'95-'98 have cats, removing/gutting them falls into another law with much worse fines.