Enforcement of the previous law and regulations in California, for example, resulted in many drivers being pulled over by state and local police and cited for improper modified exhaust systems despite having what they believed to be legal aftermarket exhausts. To prove our point (and educate ourselves) about the widespread improper enforcement of the previous California exhaust law, SEMA conducted a series of exhaust noise tests in early April 2001. First, we contacted California SAN members to see how many folks had received citations for excessive or modified exhaust. We were surprised and dismayed to learn how many fit the category! We then invited them to have their cars tested to see if they actually complied with California law. Finally, we hired a board-certified acoustical engineer and did the testing according to the standards set out in California law. Long story short, of the cars we tested only one exceeded the 95db legal level.

To remedy this problem, in 2002 SEMA helped enact a new enforcement procedure in California through its model bill. The new law forces compliance with an objectively measured standard in a fair and predictable test. Through this procedure, motorists who drive vehicles legally equipped with modified exhaust systems can confirm that they comply with California's exhaust noise standard. The California Bureau of Automotive Repair began operation of the motor vehicle exhaust noise-testing program in 2003. The law also allows courts to dismiss citations for exhaust systems that have been tested and for which a certificate of compliance has been issued. Under the program, the 40 smog check stations statewide that provide referee functions are performing the test. These referee stations are issuing certificates of compliance for vehicles when tests of their exhaust systems demonstrate that they emit no more than 95 dB under the SAE test procedure. However, only those vehicles that have received a citation for an exhaust noise violation are permitted to submit their vehicle for the test. A similar standard was enacted in Maine in 2003 and Montana in 2007.

Regulating Hot Rod Emissions: Past, Present, and Future
Government regulations continue filtering into the hot rod community. The purpose of this article is to provide a chronology of events helpful to understanding the current regulatory landscape and then look into the future of what enthusiasts can expect.

It has been approximately 40 years since the government agency that became CARB first met with specialty aftermarket parts manufacturers. The agency had become aware that non-stock, emissions-related aftermarket parts were being installed on California vehicles and wanted to establish guidelines for their use. About a dozen specialty parts manufacturers attended the meeting that was convened by the agency setting "design limits" based on the most robust parts options available from the Original Equipment Manufacturers (OEM or new vehicle manufacturers). In other words, if an OEM offered any versions of "high-performance" parts as options to stock counterparts, emissions-related specialty aftermarket parts would not be allowed to exceed the design criteria of higher performance OEM components. For example, multiple carburetors, dual exhausts, camshaft specifications and similar limits to other such aftermarket parts would be the rule.