Subaru Legacy BN/BS (2015-2019) Owners Manual: State emission testing (U.S. only)

California and a number of federal states have Inspection/Maintenance programs to inspect your vehicle's emission control system. If your vehicle does not pass this test, some states may deny renewal of your vehicle's registration.

Your vehicle is equipped with a computer that monitors the performance of the engine's emission control system. Certified emission inspectors will inspect the On-Board Diagnostic (OBDII) system as part of the state emission inspection process. The OBDII system is designed to detect engine and transmission problems that might cause the vehicle emissions to exceed allowable limits. OBDII inspections apply to all 1996 model year and newer passenger cars and trucks.

Over 30 states plus the District of Columbia have implemented emission inspection of the OBDII system.

•  The inspection of the OBDII system consists of a visual operational check of the "CHECK ENGINE" warning light/malfunction indicator light (MIL) and an examination of the OBDII system with an electronic scan tool.
•  A vehicle passes the OBDII system inspection if proper operation of the "CHECK ENGINE" warning light is observed, there are no stored diagnostic trouble codes, and the OBDII readiness monitors are all complete.
• A vehicle fails the OBDII inspection if the "CHECK ENGINE" warning light is not properly operating (light is illuminated or is not working due to a burned out bulb) or there is one or more diagnostic trouble codes stored in the vehicle's computer.
•  A state emission inspection may reject (not pass or fail) a vehicle if the number of OBDII system readiness monitors "NOT READY" is greater than one. If the vehicle's battery has been recently replaced or disconnected, the OBDII system inspection may indicate that the vehicle is not ready for the emission test. Under this condition, the vehicle driver should be instructed to drive his/her vehicle for a few days to reset the readiness monitors and return for an emission re-inspection.
•  Owners of rejected or failing vehicles should contact their SUBARU Dealer for service.

Some states still use dynamometers in their emission inspection program. A dynamometer is a treadmill or roller-like testing device that allows your vehicle's wheels to turn while the vehicle remains in one place. Prior to your vehicle being put on a dynamometer, tell your emission inspector not to place your SUBARU AWD vehicle on a two-wheel dynamometer.

Otherwise, serious transmission damage will result.

The U.S. Environmental Protection Agency (EPA) and states using two-wheel dynamometers in their emission testing program have EXEMPTED SUBARU AWD vehicles from the portion of the testing program that involves a two-wheel dynamometer. There are some states that use four-wheel dynamometers in their testing program. When properly used, this equipment should not damage a SUBARU AWD vehicle.

Under no circumstances should the rear wheels be jacked off the ground, nor should the driveshaft be disconnected for state emission testing.