Emissions Notice to Customers in California
California regulates motorcycle aftermarket parts that have the potential to impact emissions. In most
cases, the sale and use of emissions related aftermarket parts on motorcycles is prohibited unless it
is either a “replacement part” as defined by California, or is a specifically authorized use of that part
as reflected in an Executive Order (“EO Part.”)
The California Air Resources Board (ARB) regulates aftermarket parts and has promulgated
regulations that essentially place all emissions related aftermarket parts into three categories:
(1) Replacement Parts
Replacement Parts are aftermarket parts that ARB considers to be functionally equivalent to the stock
part they are intended to replace, and therefore would not impact the emissions from these vehicles.
These parts are appropriate for sale and use on motorcycles used on or off the public highways. For
aftermarket exhaust systems and parts, there are two applicable scenarios:
(a) If the motorcycle’s stock exhaust system does not contain a catalytic converter, then
an aftermarket exhaust part is a replacement part as long as the part does not remove or
replace any emission control equipment originally attached to the stock exhaust system, such
as oxygen sensors.
(b) If the motorcycle’s stock exhaust system contains a catalytic converter in the
manifold section of the stock exhaust system, then an aftermarket muffler positioned
downstream from the catalytic converter (i.e. cat-back) is a replacement part as long as the
part does not remove or replace any emission control equipment originally attached to the
stock exhaust system.
(2) Executive Order Parts
Executive Order Parts are aftermarket parts that ARB has evaluated and determined do not adversely
impact emissions, and thereby are granted an Executive Order (EO), which allows the part to be
sold and used on specified motorcycles. Any aftermarket exhaust system that replaces or otherwise
impacts emission control equipment, including catalytic converters, requires an EO to be sold and
used on a motorcycle used on or off a public highway.
(3) Competition Use Only Parts
Competition Use Only Parts may not be sold or used on a motorcycle that is used on or off the public
highways other than those motorcycles used exclusively for competition. Competition Use Only Parts
are aftermarket parts that replace or otherwise interfere with the operation of an emission control
device, such as a catalytic converter or oxygen sensor, and may be sold and used on a motorcycle
that is used only for closed course competition.