1999 Subaru Impreza Owner's Manual - Page 188
1999 Subaru Impreza Manual
Page 188 highlights
State emission testing (U.S. only) WARNING Testing of a Full-Time All Wheel drive vehicle must NEVER be performed on a single two-wheel dynamometer. Attempting to do so will result in uncontrolled vehicle movement and may cause an accident or injuries to persons nearby. CAUTION Resultant vehicle damage due to improper testing is not covered under the SUBARU Limited Warranty and is the responsibility of the state inspection program or its contractors or licensees. At state inspection time, remember to tell your inspection or service station in advance not to place your SUBARU AWD vehicle on a twowheel dynamometer. Otherwise, serious transmission damage will result. Some states have started using dynamometers in their state inspection programs in order to meet their obligation under federal law to implement stricter vehicle emission standards to reduce air pollution from cars. A dynamometer is a treadmill or roller-like testing device that allows your car's wheels to turn while the car 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 twowheel dynamometers in their emission testing programs have 7-6