This action would make needed corrections and updates to source testing methods, performance specifications, and testing regulations in 40 CFR parts 51, 60, 61, and 63. For example, Method 2 inadvertently references an incorrect section; the correct section would be cited. The method detection limit would be revised in Method 26. In Performance Specification-2, the difference between span and range would be clarified to ensure that the span is chosen to be approximately two times the emission limit. The proposed rule would include numerous other changes. A similar action is developed every few years to keep rules up-to-date and to ensure that compliance testing and monitoring are done correctly.