Exhaust Emission Inspection

The Division of Motor Vehicles performs two types of exhaust emissions analysis. The first is an idle emissions test and the second is an On-Board Diagnostic (OBD II) Test. These tests enable Delaware to comply with the Federal Clean Air Act requirements for vehicle emissions testing.

Inspection Tips:

The Division requests that customers perform the following items upon entering the vehicle inspection building:

Ensure your automatic transmission is in 'Park', or 'Neutral' and have your insurance and vehicle registration card present.

• Idle Emission Test– the DMV technician places the probe into the tailpipe to begin test. This test takes approximately 1 minute to complete.
• On-Board Diagnostic (OBD II) - 

There are two steps in the OBD-II inspection. With the key on and the engine off, the inspector confirms that the MIL is functional. The inspector connects the inspection tool to the OBD II system to check the status of the system. The following is a typical OBD II connector. This test takes approximately 2 minutes to complete. The test checks for trouble codes and monitor readiness. If you have recently replaced your battery the vehicle's monitors will not be ready causing the vehicle to fail. Drive the vehicle for several days to reset the monitors prior to DMV testing. The OBD II test method will be performed for 1996 and new gasoline powered vehicles and 1997 and new diesel-powered vehicles with MGVWR less than 8,500 pounds registered in New Castle County, Kent County and Sussex County Vehicles. Additionally, testing methods for vehicles Gasoline and Diesel powered with MGVWR less than 14001 that are 2008 and newer will be OBDII for all three counties.

For additional information regarding OBD II, please feel free to access the following web sites:

OBD Diagnostic Trouble Codes
Weber State University OBD II Clearing House

OBD-II Trouble Code Chart (repairpal.com)

Please Follow These Instructions

DMV Takes Safety Seriously

DMV Associate will be in front of, in the rear of, and/or in the driver or passenger side of the vehicle while it is operating when performing these tests.

If you are unsure about any instruction given, please do not hessite to ask for assistance.

DMV Associate will assist those customers having any problems completing a portion of Delaware's inspection program.

Remember – Smoking and cell phone usage is prohibited in the inspection lanes. No pets are allowed in the inspection facilities, expect for service animals.