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U.S. motor vehicle emissions standards are intended to help achieve and maintain air quality goals that benefit human health and the environment. U.S. laws and regulations prohibit operation on public roads any motor vehicle that violates applicable emission standards. The U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), and other regulatory agencies are responsible for implementing and enforcing applicable emission standards. In particular, the U.S. Clean Air Act (CAA) prohibits “tampering”, i.e., the alteration of certified production vehicles to modify, remove, or render inoperable emissions control hardware or software. Tampering with motor vehicles emissions control systems is punishable by substantial monetary penalties. Consumers are responsible for complying with laws prohibiting tampering, and for ensuring that modified vehicles are operated in compliance with applicable U.S. laws.


It is ZFG Racing LLC’s (“ZFG,” “we,” “our”) policy not to manufacture, offer for sale, sell, convey, or otherwise transfer any product, including Handheld Devices, Pre-Loaded Tunes, or Calibrations that contain features to bypass, defeat or render inoperative the following: EGR, Rear Oxygen Sensors, SCR, DPF, NAC, DOC, or any diagnostic trouble codes (DTCs) associated with these emission controls. Products and calibrations sold by ZFG shall retain the full operation and functionality of the On Board Diagnostic System (OBD) and continue to satisfy applicable emissions requirements.


Although ZFG offers for sale products with CARB EO certifications, we maintain a site-wide policy of NO SALES TO CALIFORNIA.


In an effort to help consumers maintain compliance with emissions regulations, product descriptions on this site may include emissions-related warnings and notices. This page summarizes the emissions-related information that you may see in this website/catalog. The process of adding these descriptions is done in good faith and is a work in progress.


Products With a California Air Resources Board Executive Order (CARB EO) Number


Products within this category are identified on ZFG’s website with the corresponding California Air Resources Board (CARB) Executive Order (EO) number and the following description:




Such products are considered “Street Legal” because they have an EO from CARB. The manufacturer demonstrated through emissions testing that the use of these parts does not adversely affect vehicle emissions.


Parts with a CARB EO may be installed in accordance with the product specifications, and such vehicles may be driven on public roads. Products within this category should be installed and used properly in order to maintain compliance with emissions standards.


Products With a Reasonable Basis Determination - Emissions Testing Verified to Have No Adverse Effect on Emissions


The EPA's longstanding view is that conduct that may be prohibited by CAA § 203(a)(3) does not warrant enforcement if the person performing that conduct has a documented, reasonable basis for knowing that the conduct does not adversely affect emissions.


Products within this category have been determined -- by ZFG or the original manufacturer -- to be unlikely to adversely affect emissions of a certified production vehicle, so long as such products are installed and used in accordance with the product specifications. Emissions testing for these products, unless otherwise noted, was performed by an independent testing facility, with guidance from SEMA Garage Emissions Compliance, using good engineering judgment to test the worst-case scenario tune on the worst-case vehicle (in accordance with product specifications).


Such products are identified on ZFG’s website with the following notice:


ZFG Racing LLC Reasonable Basis File Number: XXXXX


Products within this category, to the best of ZFG’s knowledge and understanding, demonstrate a reasonable basis that they do not adversely affect vehicle emissions and retain the full operation and functionality of the On-Board Diagnostic System (OBD) Emissions Related Items, and will continue to satisfy emissions requirements, such as meeting standards within useful life or maintaining emissions performance outside useful life. Such labeling does not indicate products are 50 state legal. Consumers are advised to make sure that such parts are installed and used properly in order to maintain compliance with emissions standards.


Reasonable Basis testing under the guidance of SMEA Garage Emissions Compliance for reasonable basis often coincides with CARB EO pending. Additional documentation available upon request.


Competition Use Only Products


Products labeled or marked as "Competition Use Only" or "Track Use Only" are products manufactured by Company or others, which are not intended for use on any vehicle driven on public roads, and such products are marketed and sold by Company for installation on vehicles to be used solely for competition motorsports (“Competition Use Only Products”).


All Competition Use Only Products sold after October 1, 2021, require a signed Competition Use Waiver before the order can be processed and shipped. The Competition Use Waiver must be completed for every order containing Competition Use Only Products. The Competition Use Waiver can be found here <link to wavier> and is submitted via our portal.


Competition Use Only Products will be accompanied by the following warning:


WARNING: This is a Competition Use ONLY Product manufactured and sold for installation on vehicles to be used solely for competition motorsports, which, once such product is installed, may never be used, or registered or licensed for use upon a public road or highway. Any other use, including recreational off-road use, may be in violation of local, state, and Federal laws. ZFG Racing LLC does not implicitly or explicitly confirm the legality of using any products it sells on public roads; that is entirely the responsibility of the consumer. If a Competition Use Only Products is installed on a vehicle and that vehicle is used on a public road or highway, it may be considered in violation of the Clean Air Act and personally subject to substantial civil penalties.


Other Items


Parts that are not accompanied by any of the above notices are either considered by the manufacturer to be unlikely to affect motor vehicle emissions in most vehicle applications, when properly installed and used OR are products that do not require a CARB EO as identified by California's Bureau of Automotive Repair ( OR have an emissions status that is not known by ZFG.  Any and all questions regarding products that are not accompanied by any of the above notices and are related to emission shall be directed to the original equipment manufacturer.

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