Car Inspection in Connecticut

SUMMARY: Connecticut Emissions Inspections

Connecticut requires vehicle emissions testing every 2 years. Bring your qualifying vehicle, the $20 fee, and your test notice to a state-approved emissions test center. The type of emissions tests your vehicle undergoes depends on your vehicle. New residents must have their vehicles tested prior to vehicle registration.

Read on for more information about the Connecticut Emissions Program, including which vehicles require testing, the various types of emissions tests, and what to do if your vehicle fails or you need a waiver or extension.

New Connecticut Residents

You must register your vehicle within 60 days of becoming a resident.

Because vehicle emissions tests are required for registration, it's best to have your vehicle tested early on within those 60 days—if your vehicle requires testing.

Inspection Requirements and Exemptions

Inspection Requirements

ALL vehicles in Connecticut EXCEPT those listed as exempt (see Inspection Exemptions below) are required to undergo emissions testing.

Emissions tests are required every 2 years. You'll receive a test notice within 45 days of your CT emissions test date. Make sure your current address is on file with the DMV; otherwise, you won't receive your notice.

Additionally, a non-exempt vehicle purchased from:

  • An authorized Connecticut dealer must be emissions compliant at the time you purchase the vehicle. You can check the emissions expiration date using the vehicle identification number (VIN).
  • A private party (and the vehicle has already been registered in Connecticut) must be inspected within 30 days of registration. You won't receive a CT emissions test date notice.
  • Out-of-state must be emissions compliant before you can register it.

Contact the motorist hotline at (888) 828-8399 if you have any questions about whether and when your vehicle requires emissions testing.

Inspection Exemptions

The following vehicles are exempt from emissions tests:

  • Model year 2013 and newer.
  • Model year 1991 and older.
  • Vehicles powered exclusively by electricity (not hybrids).
  • Motorcycles.
    • Includes bicycles with attached motors.
  • Vehicles weighing 10,001 lbs. or more.
  • Composite vehicles.
    • Must have a composite vehicle title.
  • Farm vehicles.
  • Diesel powered Type II school buses.
  • Registered vehicles not designed mainly for highway use.
  • Vehicles with Dealer, Repairer, or Transporter license plates.
    • Must be for the transportation for wholesale or auction.

Completing a CT Vehicle Inspection

Use the state's Test Center tool to find CT emissions centers appropriate for your type of vehicle and the emissions tests it requires. (See About the CT Emissions Program for details on required tests.)


  • The $20 fee*.
  • Your test notice.

Once you pass your emissions test, you'll receive a Vehicle Inspection Report. For future reference, keep this report with your registration documents.

NOTE: The emissions technician can refuse to test your vehicle and issue you a Turn Away Document for reasons such as leaking fluids, unsafe tires or wheels, and more. The state provides a complete list.

* The DMV—not the test center—will collect an additional $20 fee and deny your registration renewal if you fail to have your vehicle inspected on time.

Failed Vehicle Inspections, Extensions & Waivers

You must have your vehicle repaired and retested within 60 days of the initial test. You get 1 retest for free.

Although you can make the repairs yourself or have your vehicle repaired at the repair shop of your choosing, the DMV recommends using a Certified Emissions Repair Facility.

Emissions Inspection Extensions

If you're unable to have your vehicle tested by 30 days after the due date, you might be eligible for an extension.

Qualifying reasons include:

  • Your vehicle is out of state.
    • You can still have your vehicle tested if you're located in one of these compliant states.
  • You're attending an out-of-state school.
  • You're military personnel and on active out-of-state duty.
  • Your vehicle is under repair due to an accident.

Refer to the state's Emission Testing Time Extensions for information on each application process.

Emissions Inspection Waivers

When applicable, you can apply for a:

  • Cost waiver.
    • Available after you meet the minimum required emissions repair costs of $865.
  • Economic hardship waiver.
    • Available if your annual income is at or below state and federal poverty levels.
  • Functional diagnosis waiver.
    • Available if the technician determines your vehicle doesn't require additional repairs.

Learn more about these emissions test waivers and how to apply at the state's waiver eligibility page.

About the CT Emissions Program

In addition to any or all of the tests below, all vehicles will undergo a Catalytic Converter Functional Check.

This test checks for the presence of a catalytic converter; without a catalytic converter, your vehicle will fail the emissions test.

Continue within this section for other tests your vehicle may be required to undergo.

On-Board Diagnostic (OBD) Testing

OBD tests are reserved for:

  • Gasoline-powered vehicles model year 1996 and newer.
  • Diesel-powered vehicles model year 1997 and newer that weigh under 8,501 lbs..
    • See “Diesel-Powered Vehicles" below for information on diesel vehicles model year 1996 and older or weighing 8,501 lbs. to 10,000 lbs.

OBD tests consist of connecting a cable from the testing equipment to your vehicle's on-board computer and checking factors such as the engine, transmission, and other emissions control systems.

Acceleration Simulation Mode (ASM) Testing

ASM tests are reserved for vehicles model year 1995 and older, weighing under 8,500 lbs.

ASM tests consist of inserting a probe in the tailpipe and measuring emissions while the vehicle is driven on a dynamometer at 25 MPH with the application of 25% load associated with your vehicle's make and model.

Pre-Conditioned Two-Speed Idle (PC TSI) Testing

PC TSI tests are reserved for model year 1995 and older vehicles that are any one of the following:

  • All-wheel drive.
  • Limited by traction control.
  • More than 8,500 lbs.

PC TSI tests consist of running the vehicle at 2 modes running different RPMs (while the wheels are stationary) and checking the vehicle's emissions.

Gas Cap Pressure Leak Testing

This test is reserved for gasoline-powered vehicles model year 1995 and older, and checks that your vehicle's gas cap properly seals and allows the evaporative emissions system to dispose of fuel vapors correctly.

Diesel-Powered Vehicles

These emissions tests are reserved for diesel-powered vehicles that are:

  • Model year 1996 and older.
  • Model year 1997 and newer.
    • Weight must be 8,501 lbs. to 10,000 lbs.

If your diesel-powered vehicle meets these requirements, it will undergo either a:

  • Loaded Mode Diesel (LMD) Opacity test.
    • Uses the dynamometer.
  • Modified Snap Acceleration (MSA) test.
    • Measures smoke density from your vehicle's tailpipe using an opacity meter.

Your emissions test technician will inform you which test your vehicle requires.

NOTE: If your diesel-powered vehicle is a model year 1997 and newer and weighs fewer than 8,501 lbs., refer to “On-Board Diagnostic (OBD) Testing" above.

Connecticut Incentives for Eco-Friendly Driving

As mentioned above, fully electric vehicles are exempt from smog and emissions testing.

To be clear, this means vehicles that run solely on electricity. Hybrids that partially run on electricity are not included.

For more information about eco-friendly driving perks, such as auto insurance discounts and tax incentives, visit our page on green driver incentives.

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