California laws specifically prohibits motorcycle owners from using any aftermarket product which would require the removal of any emissions control related components and or parts unless the part is either (1) a “replacement part”, (2) a part that has been approved for use by and ARB Executive Order, or (3) a part which is to be used for “competition use only.”
1) “Replacement Parts” – replacement parts are aftermarket parts that have the same function and effect on emissions as the parts they are replacing. This means that if a vehicle was not originally equipped with a catalyst and all other emissions related controls that were connected like oxygen sensors (O2 Sensors) are reconnected, then the part is considered a Replacement Part. If the vehicle does have a catalyst and the installation of the part does NOT remove the catalyst (ie. cat back system) and all other emissions related controls are reconnected, then this is also considered a replacement part. Slip on mufflers in applications where the catalyst is not contained in the original muffler are an example of a replacement part. Full system exhausts when installed on vehicles that did not originally contain a catalyst and whose design allows the reinstallation and original function of any other emissions control related components are also considered replacement parts.
2) Executive Order Parts are emissions-related aftermarket parts that ARB has evaluated and determined do not adversely impact emissions. An Executive Order (EO) is the document signed by an ARB official documenting ARB approval for specified motorcycles. Any aftermarket exhaust system that replaces or otherwise impacts emission control equipment, including catalytic converters, requires an EO to be sold for use in California unless the system is for competition use only.
3) Competition use only – parts that are used exclusively in competition on race only vehicles. These parts do not require approval as long as they “are not used on public highways”. Labeling a product as being for “Racing Only” or “Closed Course Competition” is not sufficient for it to be included under this classification. It must be a competition vehicle and must not be used at any time on a California public highway.
For more information on the California Air Resource Board please click here.
You may also wish to visit the MIC website for additional information on aftermarket exhaust systems click here.