Stop CARB Act of 2025

This bill repeals federal waivers that allow California to set its own vehicle and engine emission standards under the Clean Air Act. It directly affects California's Air Resources Board (CARB), prohibiting the state from adopting or enforcing standards for nonroad engines (like construction equipment, farm vehicles, and locomotives) or new motor vehicles. Key provisions include removing federal authorization for California's vehicle standards (Section 177) and invalidating all existing waivers for state emission rules. The bill would eliminate California's ability to enforce its own emission requirements for these categories, shifting authority entirely to federal standards.