http://www.in.gov/legislative/ic/cod...9/ar19/ch8.pdf
Looks like DSMgirl is right, the law in IN, like many other places, is written so vauge that a officer of the law can be having a bad day and pull you over.
The law here in SLC is not a vauge as your code, but the added tidbits like: No person shall sell, furnish, provide or purchase, nor shall any person attach to any vehicle any device which will or is intended to increase or change the character of the sound of the original muffling
But with the openeing line of: Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation. Notwithstanding the foregoing...
Some of these laws are just bull.. I have seen potholes in the road here that can alter the sound of the exhaust permanatly.
SLC Code:
http://66.113.195.234/UT/Salt%20Lake...0000011000.htm