California Vehicle Code
Section 27156 and the Federal Clean Air Act prohibit modifications to vehicles that increase motor vehicle emissions. Most performance modifications do not increase vehicle emissions and if proven by their manufacturers and the ARB not to increase vehicle emissions, are allowed an exemption to allow for their installation on vehicles in California. Aftermarket parts or modifications shown to not increase vehicle emissions are granted an exemption to emission control system anti-tampering laws.
This exemption is called an Executive Order (EO) and allows the modification to be installed on specific emissions-controlled vehicles. Every Executive Order part or modification has an assigned number that can be verified by Smog Check stations, BAR Referee stations, or by the California Air Resource Board.
Products sold and manufactured by ASMC Ltd. dba ALTA & PERRIN Performance may not have exemption in California and therefore are for Off-Road Use Only. These products have clear and reasonable warning labeling on the products web page(s) and packaging of the part. The warning has text similar to: Off-Road Use Only. This product is legal in California only for racing vehicles which may never be used upon a highway. Check your local and federal laws prior to installation.
You will be prompted during checkout to acknowledge that you have received and understand this warning.
Learn more by going to https://www.arb.ca.gov/msprog/aftermkt/aftermkt.htm