Information About Anti-Tampering Laws
Federal and state noise and emissions laws regulate modifications
that affect emissions from motor vehicles, including motorcycles. Before
purchasing any emissions-related products for use in California,
you should carefully review the information provided herein as California
law prohibits the installation and use of many aftermarket
emissions-related parts on California highways, and authorizes the
recovery of substantial fines and penalties against those who violate
California emissions laws. Modifications that increase vehicle emissions
can be illegal in certain states in addition to California.
• The exhaust parts in this catalog are generally not legal for sale,
use or use in California, unless such parts are installed on vehicles
that did not come originally equipped with a catalytic converter OR
such parts either have received Executive Order (EO) from CARB’s
Executive Officer or are installed on racing vehicles which are never
used upon California highways. Do not purchase, sell, install or
use any of the exhaust parts in this catalog in California unless you
have determined that one or more of these conditions apply. End
use customers should check with the manufacturers of their vehicles
or CARB to determine whether such vehicles came originally
equipped with catalytic converters.
• California law generally prohibits the removal of catalytic converters
from motorcycles that are used in California.
• In California, it is generally illegal to replace an OEM exhaust part
that contains a catalytic converter with an aftermarket part that
does not contain a catalytic converter.
• Aftermarket exhaust parts intended for installation on non-catalyst
equipped motorcycles are generally presumed to be legal for sale,
installation and use in California.
• Aftermarket slip-on mufflers that do not contain catalytic converters
are generally legal for use in California unless the muffler being
replaced contained a catalyst.
• Aftermarket exhaust parts that contain catalytic converters are generally
illegal for sale, installation and use unless they have been
exempted and certified by CARB’s Executive Officer. Lists of exempted
products are available on CARB’s website and can be accessed
via the hyperlinks provided below.
• California’s air pollution control requirements do not generally
apply to racing vehicles, which are used in closed course competitions
and are never used on California highways.
Add-on and Modified Parts
California emissions laws prohibit the installation, sale, advertising,
and on- and off-highway use of any add-on or modified emissions-
related part (e.g., exhaust parts or systems) on any
pollution-controlled vehicle unless either (a) the part has received an
exemption from the Executive Officer (EO) of the California Air Resources
Board (CARB) or (b) the part is installed on a racing vehicle
which is never used upon a highway. See California Vehicle Code
§§ 27156 and 38391; see also 13 CCR §§ 2220-2225 (aftermarket
parts regulations). An emissions-related part is defined to mean any
automotive part, which affects any regulated emissions from a motor
vehicle which is subject to California or federal emissions standards.
13 CCR § 1900(3). A modified part is defined to mean any aftermarket
part intended to replace an original equipment emissions-related
part and which is not functionally identical to the original
equipment part in all respects which in any way affect emissions, excluding
a consolidated part. 13 CCR § 1900(b)(14). An add-on
part is defined to mean any aftermarket part which is not a modified
part or a replacement part. A racing vehicle is defined to mean a
competition vehicle not used on public highways. California Health
& Safety Code § 43001.
A replacement part is defined to mean any aftermarket part intended
to replace an original equipment emission-related part and which is
functionally identical to the original equipment part in all respects
which in any way affect emissions. 13 CCR § 1900(b)(20). Replacement
parts are presumed to be legal for use on pollution controlled
vehicles and do not require CARB exemptions. See 13 CCR § 2221;
see also CARB’s Replacement Parts Guidelines – Aftermarket, Performance
and Add-On Parts Regulations.
In California, exhaust systems (headers or mufflers) intended for
installation on non-catalyst equipped motorcycles are considered by
CARB to be replacement parts and comply with emissions regulations
enforced by CARB, provided that all emission controls originally connected
to the exhaust manifold are reconnected to the exhaust system
and are functioning properly. Similarly, slip-on mufflers are generally
legal for use in California as replacement parts unless the muffler
being replaced contained a catalyst. Before purchasing any exhaust
products in this catalog, check with the vehicle manufacturer to determine
whether the vehicle came originally equipped with a catalytic
converter. Before purchasing any slip-on muffler products in this catalog,
check with the vehicle manufacturer to determine whether the
OEM muffler contains a catalyst.
CARB Executive Orders
The manufacturers of aftermarket add-on and modified parts are
responsible for obtaining exemptions from CARB. Any add-on or
modified emissions-related parts contained in this catalog that are
subject to noise or emissions laws may or may not have been evaluated
and/or exempted by CARB or other applicable enforcement
For a list of CARB Executive Orders by device (except for
catalytic converters), see http://www.arb.ca.gov/msprog/aftermkt/
devices/amquery.php For a list of CARB-exempted aftermarket
critical emission control parts for highway motorcycles, see
pdf. See also CARB’s webpage on Motorcycle Aftermarket
As a distributor, Motorcycle Garage USA makes no representation or warranty
with respect to whether the items in this website are legal for
sale, installation or on-highway use in California or in any other state.
Customers that purchase, install, and use the emissions-related products
in this catalog must comply with all applicable laws. When purchasing,
installing and using add-on or modified aftermarket parts,
the purchaser is responsible for ensuring that such parts are replacement
parts, have received CARB exemptions or will be installed on
racing vehicles which are never used upon California highways.
Consult with the manufacturer as to any such exemptions before purchasing
any add-on or modified emissions-related parts for use in
California or elsewhere.
For additional information about the sale and use of aftermarket
exhaust systems in California, see the Motorcycle Industry Council’s
responses to Frequently Asked Questions about Aftermarket Exhaust
Systems for Motorcycles and ATVs in California.