The Stop CARB Act of 2024 would eliminate California's authority to set its own vehicle emission standards under federal law. Currently, California is allowed to adopt stricter pollution controls than federal standards, and other states can choose to follow California's standards instead of the weaker federal rules. This bill would repeal those provisions, eliminating California's special waiver status and preventing other states from adopting California emission standards. The legislation would also nullify all existing waivers that California previously received and deny any pending waiver applications. The bill has no specific funding provisions or implementation timeline beyond taking effect upon enactment.