What must diesel programmers provide to be legal?

Diesel programmers must provide proof of EPA or CARB certification to be legal. This certification confirms that the emissions control technologies used in the diesel programs comply with federal and/or state regulations regarding air quality standards. The Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) are the regulatory bodies that set these standards, ensuring that any modifications made to a diesel vehicle do not violate emissions limits. By obtaining this certification, manufacturers and programmers demonstrate that their products meet the necessary environmental standards, making their use in vehicles legal and in compliance with environmental laws.

Other aspects like vehicle registration and manufacturer's warranty are important for vehicle operation but do not specifically address the emissions compliance required by regulations. Similarly, registering with the local DMV is a part of vehicle operation but does not pertain to emissions control certifications.