2008 Subaru Tribeca Owner's Manual - Page 240

7-6 Starting and operating in order to meet their obligation under federal law to implement stricter vehicle emission standards to reduce air pollution from vehicles. 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. Depending on the severity of a state's air pollution problems, the states must adopt either a "basic" or "enhanced" vehicle emission inspection test. Normally, a portion of the basic emission test consists of an emission inspector inserting an analyzer probe into the exhaust pipe of an idling vehicle for a short period of time. States with more severe air pollution problems are required to adopt an enhanced vehicle emission test. This test simulates actual driving conditions on a dynamometer and permits more accurate measurement of tailpipe emitted pollution than the basic emission test. The U.S. Environmental Protection Agency (EPA) and states using two-wheel dynamometers in their emission testing programs 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 programs. When properly used, that equipment will not damage an AWD SUBARU vehicle. Under no circumstances should the rear wheels be jacked off the ground, nor should the driveshaft be disconnected for state emission testing. The EPA has issued regulations for inspecting the On-Board Diagnostic (OBD) system as part of the state emissions inspection. The OBD system is designed to detect engine and transmission problems that might cause vehicle emissions to exceed allowable limits. These inspections apply to all 1996 model year and newer passenger cars and light trucks. Over 30 states plus the District of Columbia have implemented the OBD system inspection. . The inspection of the OBD system consists of a visual operational check of the "CHECK ENGINE" warning light/ malfunction indicator lamp (MIL) and an examination of the OBD system with an electronic scan tool while the engine is running. . A vehicle passes the OBD system inspection if proper the "CHECK ENGINE" warning light/MIL illumination is observed, there is no stored diagnostic trouble codes, and the OBD system readiness monitors are complete. . A vehicle fails the OBD inspection if the "CHECK ENGINE" warning light/MIL is not properly operating or there is one or more diagnostic trouble codes stored in vehicle's computer with the "CHECK ENGINE" warning light/MIL illuminated. . A state emission inspection may reject (not pass or fail) a vehicle if the number of OBD system readiness monitors "Not Ready" is greater than one. Under this condition, the vehicle operator should be instructed to drive his/her vehicle for a few days to set the monitors and return for an emission re-inspection. . Owners of rejected or failing vehicles should contact their SUBARU Dealer for service.