Vehicle Inspection

Vehicles with malfunctioning emission controls emit about three to four times more air pollution than federal standards allow. Of the approximately one million vehicles DEQ tests every two years, about 6 percent fail. Many of those that fail simply require proper tuning before being retested. There is no charge if your vehicle fails the test. Adjustment or repairs to your vehicle may be made by anyone - a garage mechanic, auto dealership, service station technician, or yourself.

Oregon law prohibits disconnecting, altering or modifying required pollution control equipment. If this equipment has been removed or modified, it won't pass the vehicle inspection test and the equipment will need to be reinstalled or repaired.

Note for model year 1996 and newer vehicles: When the Check Engine light is illuminated on your dashboard, your car will not pass DEQ’s test and is in need of repair. Once your vehicle receives repair and the Check Engine light has turned off, be sure your mechanic explains the drive cycles your vehicle must experience prior to going through DEQ’s test. Otherwise, if you test too early after a repair, your test results will be “Unready”; meaning your vehicle’s computer hasn’t finished evaluating all of the emission control equipment

DMV trip permits

Trip permits must be obtained from a DMV Office. Since Jan. 1, 2002, a vehicle may be issued only two 21-day trip permits in a 12-month period. The fee for a 21-day trip permit is $33. The DEQ cannot issue trip permits.

DEQ-recognized automotive repair shops

DEQ maintains a list of Recognized Automotive Repair Shops​ in the Portland-Metro area. The list is simply a consumer guide to repair facilities that have the required diagnostic equipment and trained technicians available to make emission testing related adjustments and repairs.

Smoking vehicles

If your vehicle has failed for excessive visible smoke please read our Smoking Vehicles Fact Sheet | Autos Emitiendo Humo en Exceso​.

Estimated cost of repairs

Costs depend on the nature of the repair. Newer vehicles may be covered by a manufacturer's warranty entitling owners to free repairs at a dealership or other authorized repair facility. Check your vehicle's warranty documents.

Clean Air Partners Program

Low-income residents in the Portland area can participate in the Clean Air Partners Program. To qualify the vehicle must be 1996 or newer, have failed the OBD test and require minor repairs to the emission control system. Donations collected for the CAPs program are used to help those in need, repair their vehicles, pass the vehicle inspection test and drive cleaner, less polluting vehicles. For more information read our Clean Air Partners Fact Sheet​ or call 971-673-1630 ext. 0.


For questions or feedback on the Vehicle Inspection Program, visit our Questions and Comments page, or call one of our area contact numbers below:

  • Portland Area: 503-229-5066
  • Medford Area: 541-776-6145
  • Toll-Free in Oregon: 877-476-0583
  • Hearing Impaired: 711