---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchC/part51/subpartS"
level: "subpart"
label: "Subpart S"
heading: "Inspection/Maintenance Program Requirements"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchC-part51-subpartS"
sections_count: 24
---

# Subpart S — Inspection/Maintenance Program Requirements

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter C — Air Programs › Part 51 — Requirements for Preparation, Adoption, and Submittal of Implementation Plans

## Sections

- [§51.350. Applicability.](/cfr/40/51.350.md)
- [§51.351. Enhanced I/M performance standard.](/cfr/40/51.351.md)
- [§51.352. Basic I/M performance standard.](/cfr/40/51.352.md)
- [§51.353. Network type and program evaluation.](/cfr/40/51.353.md)
- [§51.354. Adequate tools and resources.](/cfr/40/51.354.md)
- [§51.355. Test frequency and convenience.](/cfr/40/51.355.md)
- [§51.356. Vehicle coverage.](/cfr/40/51.356.md)
- [§51.357. Test procedures and standards.](/cfr/40/51.357.md)
- [§51.358. Test equipment.](/cfr/40/51.358.md)
- [§51.359. Quality control.](/cfr/40/51.359.md)
- [§51.360. Waivers and compliance via diagnostic inspection.](/cfr/40/51.360.md)
- [§51.361. Motorist compliance enforcement.](/cfr/40/51.361.md)
- [§51.362. Motorist compliance enforcement program oversight.](/cfr/40/51.362.md)
- [§51.363. Quality assurance.](/cfr/40/51.363.md)
- [§51.364. Enforcement against contractors, stations and inspectors.](/cfr/40/51.364.md)
- [§51.365. Data collection.](/cfr/40/51.365.md)
- [§51.366. Data analysis and reporting.](/cfr/40/51.366.md)
- [§51.367. Inspector training and licensing or certification.](/cfr/40/51.367.md)
- [§51.368. Public information and consumer protection.](/cfr/40/51.368.md)
- [§51.369. Improving repair effectiveness.](/cfr/40/51.369.md)
- [§51.370. Compliance with recall notices.](/cfr/40/51.370.md)
- [§51.371. On-road testing.](/cfr/40/51.371.md)
- [§51.372. State Implementation Plan submissions.](/cfr/40/51.372.md)
- [§51.373. Implementation deadlines.](/cfr/40/51.373.md)