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State of New Jersey-Department of Environmental Protection-Bureau of Mobile Sources
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The intent of the diesel inspection program is to identify diesel vehicles with excessive smoke emissions as these emissions are an indicator of poor vehicle maintenance and contribute to air pollution. Diesel engines emit soot, or black carbon particles which then become airborne.
 The diesel inspection program is jointly administered by the NJ Motor Vehicle Commission (MVC), the NJ State Police (NJSP), and NJDEP. The 75,000 vehicles that are subjected to annual inspections must pass an emission test for smoke opacity within 90 days of their annual registration. Inspections are performed at licensed diesel PIFs under our Periodic Inspection Program. The Roadside Enforcement Program fields teams of MVC inspectors and State Police. Smoking vehicles and excessive idling of diesel engines are also prohibited.
To ensure the annual and roadside inspection programs operate effectively, the Diesel I/M unit:

  • Develops and refines the procedures and standards for testing diesel vehicles
  • Collects and analyzes inspection data from the licensed inspection centers as well as the roadside teams
  • Audits the roadside teams to ensure proper operation of equipment and correct procedures
  • Coordinates with the NJ MVC on licensing procedures and enhancements to these two inspection programs.

This unit maintains its leadership role by promulgating more stringent inspection requirements for heavy duty vehicles. This unit continues to explore ways to enhance its program by increasing outreach, developing partnerships, and testing new equipment and concepts.

All HDDVs, New Jersey registered or out of state, are subject to random roadside inspections. Teams of MVC inspectors and State Police monitor a network of inspection sites that cover the entire state. The inspection sites are selected to provide maximum safety for the motoring public, the truck drivers, and the inspection team. The roadside inspection utilizes the snap-acceleration test, one of three test methods adopted by NJDEP. Penalties, in the form of fines, are issued for exceeding the emission standards, and for failing to have the annual inspection performed.

All diesel-powered vehicles 18,000 pounds or more GVWR must undergo an annual emissions inspection within 90 days after the date of initial or renewed registration. The inspection, which utilizes one of the three test methods adopted by NJDEP, must be performed at a MVC licensed diesel Private Inspection Facility (PIF). A network of almost 300 diesel PIFs has been developed across the state, in all 21 counties.
Not all diesel PIFs are repair facilities. If your vehicle needs repairs or maintenance, check with your local diesel PIF to see if they provide the services you need.
Find a diesel PIF near you: New Jersey Motor Vehicle Commission
Find out more information on diesel PIF reporting requirements.

Established by Public Law 1995, Chapter 157, the rules that govern the heavy duty diesel inspection and maintenance are:
NJ Department of Environmental Protection
N.J.A.C. 7:27-14 - Control and Prohibition of Air Pollution from diesel- fueled Motor Vehicles
N.J.A.C. 7:27B-4 - Air Test Method 4: Testing procedures for Motor Vehicles
NJ Department of Transportation
N.J.A.C. 13:20-26 - Periodic Diesel Inspection Program
N.J.A.C. 13:20-46 - Diesel Emission Inspection and Maintenance Program
N.J.A.C. 13:20-47 - Diesel Private Inspection Facility - Licensing
NJ State Police
N.J.S.A. 39:8-59 - 76 - Periodic Diesel Inspection Program