• Policy guidance on inspection and maintenance (I/M) program implementation
• Inspection and Maintenance (I/M) Procedures
• IM240 Technical Guidance
• Acceleration Simulation Modes (ASM)

Policy guidance on inspection and maintenance (I/M) program implementation.

• Guidance on Biennial Performance Evaluation Requirements for Enhanced Vehicle Inspection and Maintenance (I/M) Programs (PDF) (16 pp, 527 K, June 2020, EPA-420-B-20-040)
  This document provides guidance to clarify how the biennial performance evaluation requirements can be met for states with enhanced I/M programs.
• Guidance on Vehicle Inspection and Maintenance (I/M) Test Data Statistics as Part of Annual I/M Reporting Requirements (PDF) (12 pp, 270 K, May 2020, EPA-420-B-20-033)
  This document provides guidance to help states and local agencies develop required annual reports for I/M programs.
• Guidance for On-Road Testing Requirements for Enhanced Vehicle Inspection and Maintenance (I/M) Programs (PDF) (8 pp, 169 K, March 2020, EPA-420-B-20-020)
  This document provides guidance to clarify how the on-road testing requirement can be met in states with enhanced I/M programs.
• December 2016 policy guidance entitled Vehicle Emission Inspection and Maintenance (I/M) Provision in the Fixing America’s Surface Transportation (FAST) Act provides clarification regarding the obligations of states versus EPA with regard to the I/M provision of the FAST Act exempting certain replica vehicles from I/M.
• February 2014 modeling guidance document entitled Performance Standard Modeling for New and Existing Vehicle Inspection and Maintenance (I/M) Programs Using the MOVES Mobile Source Emissions Model (PDF) (25 pp, 246 K, EPA-420-B-14-006, January 2014) provides clarification on how to quantify I/M emission reductions for planning purposes using the MOVES generation of mobile source emission factor models, including a discussion of I/M modeling changes since the previous mobile source emission factor model, MOBILE. This guidance corrects technical issues identified in an earlier version released November 2013 (23 pp, 242 K, EPA-420-B-13-059, November, 2013).The current version replaces that earlier document.
• May 12, 2004 policy memo signed by Tom Helms (Ozone Policy and Strategies Group) and Leila Cook (State Measures and Conformity Group) entitled 1-Hour Ozone Maintenance Plans Containing Basic I/M Program provides clarification on how the CAA's anti-backsliding provisions apply under the 8-hour standard with regard to certain categories of vehicle inspection and maintenance (I/M) programs.
• October 3, 2002 Guidance Memo and Attachment, signed by Margo Oge, entitled "Considerations for State I/M Program Optimization" provides a list of questions and/or issues states should consider as they make choices about their existing and/or future I/M programs.
• EPA guidance on Model Year Exemption Policy (PDF) (2 pp, 9 K, EPA420-S-99-007, December, 1999)
• The Calculation of I/M Waiver Adjusted for CPI (PDF) (2 pp, 8 K, EPA420-B-99-011, December 1999) is the methodology that states should use to determine the minimum repair expenditure limit for waiver under 51.360 of the I/M rule.

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Inspection and Maintenance (I/M) Procedures

The IM240 Transient I/M Dynamometer Driving Schedule and The Composite I/M Test Procedure (PDF) (EPA-AA-TSS-91-1, 18pp, 154K, January 1991)

IM240 Technical Guidance

• November 2000 Inspection/Maintenance Testing Lookup Tables, v 1.8.5
  • Read Me File (TXT)(1 pg, 42 K)
  • Data Format (TXT)(1 pg, 9 K)
  • Lookup Table Data (EXE) (412 K)
  • Final Report: I/M Lookup Table Update (PDF) (41 pp, 127 K, EPA-420-B-00-100, October 2000)
• IM240 & Evap Technical Guidance (PDF) (113 pp, 1.8 M, EPA420-R-00-007, April 2000)
  • Fast Pass Coefficients & Example Calculations (ZIP XLS) (516 K)
• August 1998 IM240 and Evap Technical Guidance (EPA420-R-98-010, August 1998, replaces 3/98 draft revised guidance)
  • Full Report (PDF) (112 pp, 1.3 M, EPA420-R-98-010, August 1998)
• June 1996 Draft Revised IM240 Technical Guidance: High-Tech I/M Test Procedures, Emission Standards, Quality Control Requirements, and Equipment Specifications:  IM240 and Functional Evaporative System Tests (PDF) (87 pp, 414 K, EPA-AA-RSPD-IM-96-1, June 1996)
• July 1994: High Tech Inspection and Maintenance Tests (Procedures and Equipment) (PDF) (6 pp, 70 K, EPA 400-F-93-005, July 1994)
  High-Tech Tests for High-Tech Vehicles

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Acceleration Simulation Modes (ASM)

• Acceleration Simulation Mode Test Procedures, Emission Standards, Quality Control Requirements, and Equipment Specifications Final Technical Guidance (PDF) (57 pp, 1.1 MB, EPA420-B-04-011, July, 2004)
• June 26, 1996 Final ASM Test Procedure Documentation (PDF) (46 pp, 185 K, EPA-AA-RSPD-IM-96-2, July 1996)
• Evaluation of a Four-Mode Steady-State Test with Acceleration Simulation Modes (ASM) as an Alternative Enhanced I/M Test (May, 1993 Report).
  • ASM Revised Draft Test Procedure
  • Report and Appendices (PDF) (258 pp, 8.48 MB, EPA-AA-AQAB-93-01, May 11, 1993)

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