Safety Testing

Clean Air Car Check Program

Q. Why do we need emission testing?
A. The vehicle inspection and maintenance program is a requirement of the 1990 federal Clean Air Act Amendments and one part of the overall plan to improve air quality by reducing hydrocarbons and nitrogen oxides in Lake, Porter, Clark and Floyd counties. Emission testing improves air quality by ensuring emission controls are working properly. This program has contributed to better air quality in those counties.

Q. Why does my vehicle need to be tested?
A. Motor vehicles powered by gasoline are significant contributors to ground level ozone, or smog. Therefore, testing of these vehicles ensures that emission controls are working properly and, if not working properly, making the appropriate repairs to aid in the reduction of ground level ozone.

Q. How often will my vehicle need to be tested?
A. Vehicles will be tested every other year, with odd numbered model year vehicles being tested in odd years and even numbered year vehicles being tested in even years. For example, a 1990 model vehicle will be tested in 2000, 2002, 2004 and so on. A 1991 model vehicle will be tested in 2001, 2003, 2005 and so on.Motorists must present proof that their vehicle has passed an emissions test or received a waiver before a vehicle can be registered or a license plate can be renewed.

Q. How will I be notified about the emissions test?
A. The Bureau of Motor Vehicles mails a notice to vehicle owners before the vehicle registration expires. This notice will tell you if your vehicle is due for an emission test.

Q. How much does the emission test cost?
A. There is no charge for a vehicle emissions test.

Q. How will I know where to take my vehicle for testing?
A. There are nine Clean Air Car Check stations in Indiana; seven in northwest Indiana and two in southern Indiana. To determine the station nearest you, click here: Northern Indiana [PDF] or Southern Indiana [PDF] or call the Clean Air Car Check Hotline at (888) 240-1684.

Q. What if I purchase a used vehicle?
A. Before purchase, a vehicle's emission test status can be confirmed by calling the Clean Air Car Check Hotline at (888) 240-1684 or visiting a Clean Air Car Check Station. Using the vehicle identification number (VIN), the testing record can be retrieved from the CACC database. A vehicle must receive a passing emissions test and provide that proof to the Bureau of Motor Vehicles in order to register and license the vehicle.

Q. Which vehicles must be tested?
A. Passenger vehicles in model years and light-duty trucks with a GVWR of less than 9,000 pounds and an engine displacement of over 200 cubic centimeters must be tested. Model year 1976-1980 vehicles receive a single-speed idle test. Model year 1981-1995 vehicles will receive the enhanced or dynamometer test. Model year vehicles 1996 and newer will receive an OBD II test.

Q. What vehicles are exempt?
A. Vehicles which are:

• model year 1975 and older
• powered by electricity or diesel fuel
• considered "show" cars
• ceremonial vehicles
• recreational vehicles
• registered for farm use only (including tractors)

Q. What is my vehicle tested for?
A. The Clean Air Car Check will measure your vehicle's hydrocarbon (HC) and carbon monoxide (CO) emissions. High levels of HC and CO emissions from a vehicle indicate that the vehicle is not using fuel efficiently and, as a result, these emissions contribute to poor air quality.

Test Procedures

Q. What pollutants are tested?
A. Vehicles are tested for hydrocarbons and carbon monoxide. Hydrocarbons are unburned gasoline particles that contribute to the formation of ground level ozone, often reffered to as smog. (See "What is ozone?" below). Carbon monoxide is a colorless, odorless gas formed from partially burned fuel that can adversely affect mental fuction, visual focus, alertness, and can even cause death.

Q. How does the test procedure work?
A. For model year vehicles 1981 through 1995, the emissions check has three steps. During the first step, an inspector will complete a basic visual inspection for leaking fluids and conditions that may present a safety problem. The motorist will be asked for registration information so that the vehicle identification number can be verified. The motorist will then be asked to exit the vehicle and proceed to an enclosed, climate controlled waiting area. The lane inspector will then inspect for the presence of the catalytic converter and conduct a gas cap pressure test.

During the second step, the vehicle is placed on the dynamometer, a treadmill-like device, and secured in place. The lane inspector will enter the vehicle and "drive" the vehicle, following a drive trace projected on a computer screen. "Driving" the vehicle on the dynamometer simulates normal driving, such as accelerating, decelerating, braking and stopping. The vehicle is operated between speeds of 0-33 mph. Emissions are collected as the vehicle is driven. If a vehicle does not pass the emission test during the first testing cycle, a second-chance test is automatically given. When the test is completed, the lane inspector exits the vehicle. (NOTE: During the second step, a well-maintained vehicle may be able to "fast pass" after the first 30 seconds of the emissions test.)

During the third step, the motorist returns to the vehicle. At this time the inspector returns the motorist's registration information and presents the vehicle emission test results. Additional information flyers may be given out at this time also.

For model year vehicles 1976-1980, the three testing steps are similar except that these vehicles will not be tested on the dynamometer. The vehicle emissions are checked while the vehicle is idling.

Model year 1996 and newer vehicles are administered an OBD II system test. This test does not require that the vehicle be driven on the dynamometer. A scan tool will be hooked up to the vehicles OBD connector to check the OBDII system status.

Q. Why do all of the car accessories need to be turned off?
A. Electrical accessories can interfere with the electronic sensing of the engine speed and can also adversely affect the test results.

Q. How long will the test take?
A. Once the vehicle enters the first testing position, the three-step test should only take about ten minutes.

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