The 1990 Clean Air Act Amendments authorized the U.S. Environmental Protection Agency (EPA) to require state’s to implement stricter vehicle emission control inspection programs in order to reduce air pollution from cars. Depending dson the severity of a state’s air pollution problems, the state was to 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 the vehicle during idle driving conditions for a short period. States with more severe air pollution problems were required to adopt an enhanced vehicle emission test, which is usually limited to major metropolitan areas of 200,000 or more people. The enhanced test simulates actual driving conditions on a dynamometer, which permits more accurate measurement of tailpipe emitted pollution than the basic emission test.
By 1999, about 18 states are expected to have implemented some form of dynamometer-type testing in their enhanced emission programs. Many of these states will use a two-wheel dynamometer. These states provide owners of Full-Time 4WD or AWD equipped Subaru vehicles with a testing exemption and will perform only the basic idle tailpipe emission test. When available, Subaru approves of the state usage of four-wheel dynamometers.
Increasing numbers of Subaru AWD customers have contacted Subaru of America, Inc. and/or their authorized Subaru dealer seeking warranty reimbursement for AWD transmission damage following an incorrect two-wheel dynamometer performed emission test. These vehicle owners have reported no driveability problems prior to state enhanced emission testing, but seek repair for driveability symptoms (vibrations, noise on turns, etc.) normally within 100 miles after the improperly performed two-wheel dynamometer test.
Subaru of America, Inc.’s Emissions Defect & Performance Warranties cover only defects in vehicle materials and workmanship, and not resultant vehicle damage caused by an improper state emission inspection. Subaru Full-Time 4WD and AWD equipped vehicles should never be tested on a single two-wheel dynamometer.
In the event that the vehicle has been improperly tested and exhibits the driveability symptoms described above, customers are urged to contact an authorized Subaru dealer or Subaru of America, Inc. immediately. We recommend that all post emission testing repairs be performed at an authorized Subaru dealer to help ensure that the repairs are properly performed.