If its not stock its illegal period.

http://leg1.state.va.us/cgi-bin/legp...+cod+46.2-1049

§ 46.2-1049. Exhaust system in good working order.

No person shall drive and no owner of a motor vehicle shall permit or allow the operation of any vehicle on a highway unless it is equipped with an exhaust system of a type installed as standard factory equipment, or comparable to that designed for use on the particular vehicle as standard factory equipment, in good working order and in constant operation to prevent excessive or unusual noise. An exhaust system shall not be deemed to prevent excessive or unusual noise if it permits the escape of noise in excess of that permitted by the standard factory equipment exhaust system of private passenger motor vehicles or trucks of standard make.

The term "exhaust system," as used in this section, means all the parts of a motor vehicle through which the exhaust passes after leaving the engine block.

Chambered pipes are not an effective muffling device to prevent excessive or unusual noise.

(Code 1950, § 46-305; 1952, c. 455; 1956, c. 651; 1958, c. 541, § 46.1-301; 1960, c. 120; 1970, c. 266; 1972, c. 66; 1989, c. 727.)