Vehicle Inspection and Maintenance

The Delaware Vehicle Inspection and Maintenance (I/M) program is a mandatory control measure to help the State of Delaware meet the National Ambient Air Quality Standard (NAAQS) for ozone.

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Deanna Morozowich
Division of Air Quality

The State of Delaware currently exceeds the NAAQS standard for Ozone. Ozone is formed by photochemical reactions between hydrocarbons (HC) and nitrogen oxides (NOx) in the atmosphere.

Both hydrocarbons and nitrogen oxides are found in vehicle emissions and are controlled by vehicle emissions control systems.

Regular Inspections

Under the Inspection and Maintenance program, vehicles undergo emissions testing or emission control systems testing as part of the vehicle registration or renewal process. By requiring that vehicles with excess emissions or malfunctioning emissions control systems be repaired and/or maintained, the motor vehicle emissions testing program is a meaningful element of Delaware’s State Implementation Plan (SIP) to meet federal air quality standards.

Motor vehicle emissions testing is performed on all gasoline and diesel-powered light-duty vehicles weighing up to 8,500 pounds gross vehicle weight at Delaware Division of Motor Vehicles inspection facilities.

The inspection requirement is biennial, requiring vehicles to pass safety and emission inspections once every other year. Inspections are performed at no charge to the vehicle owner. The first seven model years are exempt from emissions testing.

The program is managed under two regulations, the Motor Vehicle Emissions Inspection Program (Sussex County) (7 DE Admin. Code 1126) and the Low Enhanced Inspection and Maintenance Program (Kent and New Castle Counties) (7 DE Admin. Code 1131), and the Motor Vehicle Emissions Inspection Program; Plan for Implementation (PFI).

Upgrading the Inspection and Maintenance Program

On Dec. 14, 2022, DNREC Secretary Shawn M. Garvin signed three Secretary’s Orders approving amendments to the regulations and upgrading the program in Sussex County to match the program in Kent and New Castle Counties.

This regulatory amendment process started with DNREC Start Action Notices 2018-04 (Regulation 1126) and 2018-05 (Regulation 1131). It included a set of public workshops in May 2022, a Fact Sheet and drafts of the regulatory changes for public review.

The amendments to the Motor Vehicle Emissions I/M Programs include:

  • A model year exemption that expands each program from five to seven years to align with Delaware Code;
  • An increase for vehicles that weigh 8,501 up to 14,000 pounds gross vehicle weight beginning with model year 2008 for the On-Board Diagnostic (OBD) test in all counties;
  •  A change to the older vehicle testing requirements to include curb idle and gas cap tests for vehicles 1995 and older;
  • A phased-in schedule for the increase in the cost of repairs to obtain an emission waiver in Sussex County; and
  • Language to prevent vehicle tampering in all counties.

The change to the Sussex County portion of the program will be implemented by the Division of Motor Vehicles starting in the Summer of 2023.

Certified Emission Repair Technicians

Under the state’s motor vehicle emissions regulations, automotive repair technicians may become certified emission repair technicians and may apply for a permit to conduct on-road OBD-II drive-cycle testing on vehicles without current registration.

Certification may require advanced training. In some cases, work by a Certified Emission Repair Technician will count towards a DMV inspection waiver.

Applications for the Certified Emission Repair Technicians permit are managed through the DNREC ePermitting system, which offers online applications and allows users to manage their own portfolio of permits.