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Aftermarket, Performance and Add-On Parts
This page last reviewed May 10, 2018
Background:
What's under the hood is important to air quality. Automotive emissions account for over 50 percent of all smog-forming pollutants in California. To improve air quality, the California Air Resources Board (ARB) requires vehicle manufacturers to develop engine and emission equipment systems that reduce the specific pollutants that cause California's severe air quality problem. These emission control systems are also required to be proven durable and reliable.To ensure that these systems operate as designed, California Vehicle Code Section 27156 and the Federal Clean Air Act prohibit modifications that increase motor vehicle emissions. Since if properly designed, most performance modifications do not increase vehicle emissions, these same laws also allow the installation of parts or modifications proven by their manufacturers and the ARB not to increase vehicle emissions.
All aftermarket parts sold in California belong to one of the following four groups:
1. Replacement Parts - Replacement Parts Guide2. Legal Add-On or Modified Parts (Executive Order Parts) - Aftermarket Parts Database
3. Competition or Racing Use Only Parts - Exemptions for Uncontrolled Vehicles
4. Catalytic Converters
Additional Information for Manufacturers of Aftermarket Parts:
An exemption from Vehicle Code Section 27156 (VC 27156), California's anti-tampering law, is required before any add-on or modified part can be sold in California. Manufacturers interested in obtaining a VC 27156 exemption for an add-on or a modified part should fill-out and submit an application form to the ARB for evaluation. Detailed information on how to do this can be obtained from the document, "Procedures for Exemption of Add-On and Modified Parts," amended June 1, 1990. (PDF - 2.54MB)
What's New:
Workshop (05/08/18): Public Workshop to Discuss the Modification of the Aftermarket Parts Exemption Procedures.
- Webinar Information: Public Workshop to Discuss the Modification of the Aftermarket Parts Exemption Procedures.
- Mailout #: ECARS 18-02: Public Workshop to Discuss the Modification of the Aftermarket Parts Exemption Procedures.
- Slide Presentation: Public Workshop to Discuss the Modification of the Aftermarket Parts Exemption Procedures, 5/8/18. (PDF - 98K)
- Addendum Slides: Enforcement Division-CARB Competition Vehicle Update Presentation, 5/8/18. (PDF - 329K)
