Ok, here's my take on the laws. Please chime in if you have had different experiences with the judges.
California Vehicle Code 27151 specifies that you cannot modify you exhaust to make your vehicle louder than what is stated in CVC 27200.
27151. No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise emitted by the motor of such vehicle so that the vehicle is not in compliance with the provisions of Section 27150 or exceeds the noise limits established for the type of vehicle in Article 2.5 (commencing with Section 27200) of this chapter. No person shall operate a motor vehicle with an exhaust system so modified.
CVC 27200 states that the CHP has identified a distance of 50 feet to be the proper testing distance for exceeding Db levels.
27200. (a) The Department of Motor Vehicles shall not register on a dealer's report of sale a new motor vehicle, except an off-highway motor vehicle subject to identification as provided in Division 16.5 (commencing with Section 38000), which produces a maximum noise exceeding the applicable noise limit at a distance of 50 feet from the centerline of travel under test procedures established by the Department of the California Highway Patrol.
The Db levels established in 1974 are as follows:
27206. For the purposes of Section 27200, the following noise limits shall apply to any other motor vehicle, not specified in this article, manufactured:
(1) After 1967, and before 1973 ........................86 dbA
(2) After 1972, and before 1975 ........................84 dbA
(3) After 1974 .................................................80 dbA
I don't know if there have been any changes to these codes since their 1974 inception. But it looks like you were wronged by the police.
California Vehicle Code 27151 specifies that you cannot modify you exhaust to make your vehicle louder than what is stated in CVC 27200.
27151. No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise emitted by the motor of such vehicle so that the vehicle is not in compliance with the provisions of Section 27150 or exceeds the noise limits established for the type of vehicle in Article 2.5 (commencing with Section 27200) of this chapter. No person shall operate a motor vehicle with an exhaust system so modified.
CVC 27200 states that the CHP has identified a distance of 50 feet to be the proper testing distance for exceeding Db levels.
27200. (a) The Department of Motor Vehicles shall not register on a dealer's report of sale a new motor vehicle, except an off-highway motor vehicle subject to identification as provided in Division 16.5 (commencing with Section 38000), which produces a maximum noise exceeding the applicable noise limit at a distance of 50 feet from the centerline of travel under test procedures established by the Department of the California Highway Patrol.
The Db levels established in 1974 are as follows:
27206. For the purposes of Section 27200, the following noise limits shall apply to any other motor vehicle, not specified in this article, manufactured:
(1) After 1967, and before 1973 ........................86 dbA
(2) After 1972, and before 1975 ........................84 dbA
(3) After 1974 .................................................80 dbA
I don't know if there have been any changes to these codes since their 1974 inception. But it looks like you were wronged by the police.