Connecticut requires emissions testing every two years statewide for gas vehicles 4 model years and older. No safety inspection requirement. Testing is OBD-II for 1996+ vehicles and tailpipe for older cars.
Rules change. Verify the current Connecticut 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. |
| Tailpipe (pre-1996) | Two-Speed Idle test for older gas vehicles. |
| Diesel testing | Diesel vehicles 1997+ also tested. |
| Gas cap pressure check | EVAP cap test. |
| Visible smoke | Excessive smoke = fail. |
| No safety inspection | Connecticut does not check safety equipment. |
Active check engine light 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 failure is one of the top reasons cars fail in this state.
Get a Full Diagnosis →EVAP code is one of the top reasons cars fail in this state.
Get a Full Diagnosis →O2 sensor failure 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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$20 at most stations. Self-service kiosks are the same price.
Every two years, aligned with vehicle registration. New cars are exempt for the first 4 model years.
You have 60 days to repair and retest. Free retest at the same station within that window. Hardship waivers available if repair costs exceed $937.
Yes. Battery EVs are exempt. Hybrids with gas engines are tested like gas vehicles.
No. Connecticut has no statewide annual safety inspection.
Yes. The vehicle cannot be legally registered if emissions is overdue, and police will cite you.