Subaru 2003 Legacy Owner's Manual page 258

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 pro-
gram 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 sys-
tem 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.
Several states plus the District of Columbia have opted to start the OBD
system inspection prior to the required EPA regulation effective date of
January 1, 2002. Other states will add OBD system inspection in 2002.
D 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.
D 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.
D 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.
D A state emission inspection may reject (not pass or fail) a vehicle if
the number of OBD system readiness monitors "Not Ready" is greater
7-8