Oregon's DEQ (Department of Environmental Quality) runs emissions testing in the Portland metro (Multnomah, Washington, Clackamas counties) and the Rogue Valley (Medford area). Tests are required every two years for vehicles 4 model years and older. No safety inspection statewide.
Rules change. Verify the current Oregon requirements with the state DMV or environmental agency before you go. This guide reflects the program as of 2026.
| Item | What the Inspector Checks |
|---|---|
| OBD-II scan (1996+ gas) | Check engine light, codes, readiness monitors. Primary test. |
| Two-Speed Idle (older) | Pre-1996 vehicles get a tailpipe test. |
| Visible smoke | Visible smoke from exhaust or crankcase is a fail. |
| Diesel testing | Diesel vehicles 1976 and newer also tested. |
| No safety check | Oregon does not inspect brakes, lights, or tires. |
| DEQ Too app option | Many newer cars can self-test using the DEQ Too mail-in OBD-II program. |
Check engine light on is one of the top reasons cars fail in this state.
Get a Full Diagnosis →Readiness monitors not ready is one of the top reasons cars fail in this state.
Get a Full Diagnosis →Catalytic converter (P0420/P0430) is one of the top reasons cars fail in this state.
Get a Full Diagnosis →EVAP code (P0440/P0455/P0456) is one of the top reasons cars fail in this state.
Get a Full Diagnosis →Bad O2 sensor is one of the top reasons cars fail in this state.
Get a Full Diagnosis →Visible smoke is one of the top reasons cars fail in this state.
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The Portland Metro area (Multnomah, Washington, Clackamas counties) and the Rogue Valley (Medford / Jackson County area).
$25 per test at a station. Cheaper or free via DEQ Too remote testing.
Oregon's remote OBD-II testing program. You install a small dongle, drive, and the data uploads automatically. No station visit. Available for most 2005+ vehicles.
Every two years, aligned with vehicle registration renewal.
You have until your registration deadline to make repairs and retest. Repair waivers may be available if you have spent $300+ trying to fix it.
Battery EVs are exempt. Hybrids with gas engines are tested like gas vehicles.