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Vehicle emission testing

Where tests are required | When tests are required | Testing stations | Procedure

Motor vehicles are a major source of air pollutants in metropolitan areas. Vehicle exhaust emissions include carbon monoxide and volatile organic compounds (VOCs). In Southeastern Wisconsin, motor vehicles emit about one-third of volatile organic compounds (mostly hydrocarbons) and 60% of carbon monoxide present.

The federal Clean Air Act spells out air quality standards that all areas of the United States must meet. Southeastern Wisconsin is one of over 90 metropolitan areas in 35 states violating these standards. The Clean Air Act mandates the operation of state-administered vehicle emission inspection and maintenance programs in many of these areas, including Southeastern Wisconsin.

The purpose of the Wisconsin Vehicle Inspection Program (VIP) is to identify vehicles:

• With excessive exhaust emissions and require them to meet reasonable emission standards to reduce vehicle-related air pollution
• That have experienced emission equipment tampering, regardless of how caused. The owners of these vehicles are required to have "tampered" items repaired, replaced, or adjusted to proper working order before the vehicle can be registered.

Where tests are required

Effective July 1, 2008, emission inspections are required on cars and trucks with a manufacturer's gross vehicle weight rating under 8,501 pounds that are customarily kept in the Wisconsin counties of:

• Kenosha
• Milwaukee
• Ozaukee
• Racine
• Sheboygan
• Washington
• Waukesha

Exceptions are vehicles produced prior to the 1996 model year, diesel-powered vehicles, and motorcycles. Approximately 800,000 inspections are conducted each year.

WisDOT contracts with Envirotest Systems Corporation to conduct vehicle emission inspections. WisDOT audits inspection equipment and procedures at each vehicle emission test station weekly to assure accurate results. The required inspection is free.

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When tests are required

Vehicles are tested every second year at the time of renewal of license plates, beginning in the third year following the vehicle’s model year. Renewal notices indicate if testing is required. In addition, vehicles more than 5 model years old require testing within 45 days following registration by a new owner. WisDOT mails a letter to the new owner outlining the testing requirements.

When a vehicle is not tested by the license plate renewal deadline, the vehicle registration is suspended. In such cases, the owner must satisfy emissions testing to continue to legally operate their vehicle.

Testing stations

Vehicles can be inspected at any of the 11 vehicle inspection facilities located in Sheboygan and throughout southeastern Wisconsin. Note that the Waukesha south inspection facility has been closed permanently as of July 1, 2008.

Procedure

When motorists enter the inspection facility, they hand an inspector their license plate renewal notice. The inspector enters essential information into a computer to verify the vehicle's identity, weight and model year. Testable vehicles are equipped with second-generation On Board Diagnostic (OBDII) computer systems, and are inspected by means of a computer system "health-check". This check consists of plugging a scan tool into the vehicle's computer and downloading emission control systems information.

As of July 1, 2008, the program no longer conducts tailpipe testing or gas cap testing.

Motorists receive inspection results on a computer generated report form. Once a vehicle passes its inspection, the motorist may renew the vehicle's registration at the inspection facility, by mail or the Internet, or in person at any of the WisDOT DMV service centers offering vehicle registration service. All of the test facilities have the ability to process the renewals. The computer matches records from the inspection stations with WisDOT's registration records to verify that the inspection has taken place.

If a vehicle fails its inspection, the owner must pursue appropriate repair(s) prior to submitting the vehicle for re-inspection. Satisfactory completion of the inspection requirement is necessary before the owner may receive a license plate registration renewal. The inspector gives all motorists an informational brochure at the time of the initial inspection to explain the repair and retest process.

Call (414) 266-1080 or (800) 242-7510 for more information.

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Questions about the content of this page:
Bureau of Vehicle Services, bur-veh-services.dmv@dot.state.wi.us
Last modified: July 9, 2008