The following vehicles are exempt from the Connecticut Emissions Program:
- Vehicles younger than four model-years old;
- Model year 1998 and older vehicles;
- Vehicles with a gross vehicle weight rating of 10,001 pounds or more;
- Composite Vehicles (vehicle must be titled as a composite vehicle);
- Full electric-powered (non-hybrid);
- Bicycles with motors attached;
- Motorcycles;
- Certain vehicles registered but not designed primarily for highway use;
- Farm vehicles;
- Diesel – Powered Type II School Buses; (under 10,000 lbs GVWR)
- Vehicles with Dealer, Repairer, or Transporter Plates (only for the purpose of transportation during wholesale or auction).