works best with JavaScript enabled.
CARB Regulations

Emissions Regulations

Emissions Regulations Overview

Emissions-related parts are regulated under our nation’s clean air laws and are primarily enforced by two government agencies: the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board (CARB).

Exemptions for Uncontrolled Vehicles

Vehicles that were manufactured before emission control regulations took effect are called uncontrolled vehicles. Aftermarket parts regulations and anti-tampering laws do not apply to these vehicles. Uncontrolled vehicles may have any aftermarket add-on or modified part installed as long as the vehicle can still meet the tailpipe emission standards for the year of the vehicle. Uncontrolled vehicles must retain any original or retrofit crankcase control (PCV) devices and NOx device required for the year of the vehicle.

The following vehicles are considered uncontrolled vehicles:

  • 1965 and Older: U.S. Manufactured California Certified Vehicles
  • 1967 and Older: U.S. Manufactured Federally Certified Vehicles
  • 1967 and Older: Foreign Manufactured Vehicles

The Voluntary Product Labeling Program

SEMA has developed a Voluntary Product Labeling program that features color-coded labels for the identification and clarification of emissions-related add-on and modified parts. All products that are installed anywhere between the air intake and the outlet end of the catalytic converter, or that interact with the vehicle’s electronics can be grouped into the four color-coded and numbered categories listed below.

This product is covered under a CARB EO and is legal for sale and use in all 50 states.

Products that have completed the CARB EO process belong in this category. EPA recognizes the CARB EO as a reasonable basis demonstration, therefore products can be considered legal by both CARB and EPA.

Aftermarket Parts that may require an EO Number:
Air Cleaners, Cams, Carburetors, Catalytic Converters, Coils & Ignition Wires, Computer Chips, Electronic Ignitions, Distributors, Fuel Injection, Fuel Tanks, Headers, Intake Manifolds, Internal Engine Parts, Replacement Engines.

This product has met EPA's reasonable basis requirements and is legal for sale and use within the jurisdiction of the federal EPA.

This category includes products that have demonstrated a reasonable basis emissions compliance either through engineering evaluation or testing, but do NOT have a CARB EO.

There are a few reasons that a product might including (but not limited to):

  • Testing has been completed and paperwork submitted to CARB but the EO has not yet been issued.
  • The product meets the reasonable basis standard but may not meet CARB’s criteria for an EO.
  • You have performed testing but have decided not to pursue a CARB EO.

This product is not legal for street use on an emissions-controlled vehicle. It may be used on dedicated competition or pre-pollution-controlled vehicles only.

Some products can never be legal for use on pollution-controlled vehicles (both for use on the road and off-road), but they do have a legitimate use on racing vehicles and vehicles that predate emissions regulations. Pre-certification means 1965 and older domestic vehicles in California, 1968 imports in California and both domestic and imports under EPA jurisdiction.

This product does not require an EO in California. By nature of its design, it is legal for sale and use in all 50 states. Replacement parts included.

This category includes products that have little or no impact on emissions, such as drop-in air filters or exhaust components downstream of the last emissions component (such as the catalytic converter, DPF or exhaust gas sensors). Also included are devices that plug into the OBD port to monitor information, but do not alter the vehicle’s electronics.