Under the Clean Air Act, EPA is approving certain revisions, and disapproving certain other revisions, to the Nevada State Implementation Plan submitted by the Nevada Division of Environmental Protection. These revisions relate to the application of the State's vehicle inspection and maintenance program to vehicles operated on Federal installations. EPA is also correcting certain plan revisions related to this subject that EPA previously approved in error. The intended effect is to ensure that vehicles operated on Federal installations are subject only to those requirements of the State's vehicle inspection and maintenance program that apply in the same manner and to the same extent to nongovernmental entities.