Welcome to the Connecticut Emissions Program

Emissions testing using the On-Board Diagnostic system or OBD testing is the quickest and most efficient of all emissions tests.  The vehicle’s internal computer, which continuously monitors the engine, transmission and emissions control systems are tested. The OBD test is, in effect, an “early warning system” that alerts you to the need for repairs that can reduce air pollution and ensure that your vehicle keeps running as cleanly as it was designed to run.  The inspector will connect a communication cable from the emissions testing equipment to your vehicle’s Diagnostic Link Connector or DLC.  Through the cable, the emissions testing equipment will request specific communication protocols from your vehicle, allowing the testing equipment to verify whether or not your vehicle emissions control system is in compliance.  Information is retrieved from your vehicle; nothing is uploaded or installed on your vehicle.

Vehicles subject to OBD testing include 1996 and newer gasoline powered and 1997 and newer diesel powered vehicles that weigh less than 8,501 LBS.


Please click here for more information on OBD testing.