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Title 40

Displaying title 40, up to date as of 7/10/2026. Title 40 was last amended 7/09/2026.
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Title 40Protection of EnvironmentPart / Section
Chapter IEnvironmental Protection Agency1 – 1099
Subchapter CAir Programs50 – 99
Part 51Requirements for Preparation, Adoption, and Submittal of Implementation Plans51.1 – 51.1403
Subpart SInspection/Maintenance Program Requirements51.350 – 51.373
§ 51.350Applicability.
§ 51.351Enhanced I/M performance standard.
§ 51.352Basic I/M performance standard.
§ 51.353Network type and program evaluation.
§ 51.354Adequate tools and resources.
§ 51.355Test frequency and convenience.
§ 51.356Vehicle coverage.
§ 51.357Test procedures and standards.
§ 51.358Test equipment.
§ 51.359Quality control.
§ 51.360Waivers and compliance via diagnostic inspection.
§ 51.361Motorist compliance enforcement.
§ 51.362Motorist compliance enforcement program oversight.
§ 51.363Quality assurance.
§ 51.364Enforcement against contractors, stations and inspectors.
§ 51.365Data collection.
§ 51.366Data analysis and reporting.
§ 51.367Inspector training and licensing or certification.
§ 51.368Public information and consumer protection.
§ 51.369Improving repair effectiveness.
§ 51.370Compliance with recall notices.
§ 51.371On-road testing.
§ 51.372State Implementation Plan submissions.
§ 51.373Implementation deadlines.
Appendix A to Subpart S of Part 51
Calibrations, Adjustments and Quality Control
Appendix B to Subpart S of Part 51
Test Procedures
Appendix C to Subpart S of Part 51
Steady-State Short Test Standards
Appendix D to Subpart S of Part 51
Steady-State Short Test Equipment
Appendix E to Subpart S of Part 51
Transient Test Driving Cycle