The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the State of New Hampshire. This revision includes an amended regulation for the enhanced motor vehicle inspection and maintenance (I/M) program in New Hampshire. New Hampshire continues to implement a test and repair network for an on-board diagnostic (OBD2) testing program. The submitted New Hampshire regulation updates and clarifies the implementation of the New Hampshire I/M program. The intended effect of this action is to approve the updated I/M program regulation into the New Hampshire SIP. This action is being taken in accordance with the Clean Air Act.