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On-Board Diagnostics (OBD)

Status of State and Local OBD I/M Programs

A majority of the 33 state and local areas that require vehicle emissions tests have incorporated the use of OBD technology, as required by the Clean Air Act. Review the list below to find out the status of your state or locality.

For more details, visit the Equipment and Tool Institute exit EPA web site which includes a comprehensive 51 page overview of Inspection and Maintenance programs.

Currently Performing OBD Checks
  • Alaska (Fairbanks and Anchorage areas)
  • Arizona (Phoenix area)
  • California
  • Colorado(Denver and Boulder areas)
  • Connecticut
  • Delaware
  • District of Columbia
  • Georgia (Atlanta area)
  • Idaho
  • Illinois
  • Indiana
  • Kentucky (Louisville area)
  • Louisiana
  • Maine
  • Maryland
  • Massachusetts
  • Nevada (Las Vegas and Reno areas)
  • New Hampshire
  • New Jersey
  • New Mexico
  • North Carolina
  • Ohio
  • Oregon
  • Pennsylvania
  • Rhode Island
  • Utah (Salt Lake, Davis, Utah, and Weber Counties)
  • Tennessee (Davidson, Rutherford, Shelby, Sumner, Williamson, and Wilson Counties)
  • Texas
  • Vermont
  • Washington
  • Wisconsin
Will Require OBD Checks in the Future
  • Missouri (St. Louis and Franklin County)
  • New York
  • Virginia

This page is maintained by EPA's Office of Transportation and Air Quality (OTAQ).
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