Welcome to the Connecticut Emissions Program

Medium-Duty Vehicles Subject to New Emissions Testing Requirements in 2020

Based on the model year and fuel type, some medium-duty vehicles (trucks, vans, larger SUVs) with the Gross Vehicle Weight Rating (GVWR) between 8,501 LBS to 10,000 LBS will be subject to new testing requirements.

The following vehicles with the GVWR between 8,501 LBS to 10,000 LBS will be subject to the enhanced On-Board Diagnostic (OBD) test:

  • 2007 or newer diesel-powered vehicles
  • 2008 or newer non-diesel vehicles (Gasoline, Compressed Natural Gas (CNG), Liquid Propane Gas (LPG), Ethanol and Methanol)

The OBD system continuously monitors the electronic sensors and emissions control systems, including the catalytic converter, while the vehicle is being driven to ensure they are working as designed. When a potential problem is detected, a dashboard warning light called a malfunction indicator light (MIL) illuminates to alert the driver of a problem.

An OBD emission test provides a more comprehensive picture of a vehicle’s emissions status because it evaluates emissions control systems during everyday driving conditions, whereas a tailpipe test measures emissions only at a particular moment in time.

Medium-duty vehicles with the GVWR between 8,501 LBS to 10,000 LBS (2007 or newer Diesel-powered and 2008 or newer Non-Diesel vehicles) are equipped with an OBD system and can receive the more comprehensive OBD emissions test.

Please click here for more information on OBD testing.

Older Medium-Duty Vehicles with the GVWR between 8,501 LBS to 10,000 LBS

2006 and older diesel-powered vehicles will receive a test called the Modified Snap Acceleration (MSA) test that utilizes an opacity meter, which measures the smoke density emitted from the vehicle’s tailpipe.

2007 and older non-diesel vehicles will receive the Pre-Conditioned Two-Speed Idle (PC TSI) test that measures tailpipe emissions.

Where do I find the GVWR?

The GVWR weight rating is listed on the manufacturer’s vehicle identification label, usually located on the drivers’ door jam or on the drivers’ door itself.

If you need assistance finding your GVWR or have any questions related to the Connecticut emissions program, please call the motorist hotline at 1-888-828-8399.