State Emission Testing (U.s. Only) - Subaru 1998 Impreza Owner's Manual

State emission testing (U.S. only)

WARNING
Testing of an 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 acci-
dent 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 I/M Program or its contractors or licensees.
The 1990 Clean Air Act Amendments require the Environmental Protec-
tion Agency (EPA) to implement programs to reduce air pollution from
motor vehicles. States are required to adopt either a "basic" or
"enhanced" vehicle Inspection/Maintenance (I/M) Program depending
on the severity of their air pollution problem. The "enhanced" I/M test
simulates actual driving conditions on a dynamometer and permits more
accurate measurement of tailpipe emissions than the "basic" I/M test
which measures emissions only during engine operating conditions at
idle and 2,500 RPM with no engine load. The "enhanced" I/M test also
includes a pressure check to identify evaporative emissions leaks in the
fuel system.
The U.S. EPA has EXEMPTED SUBARU Full-Time All-Wheel Drive (AWD)
vehicles from the following performance warranty short tests:
D Loaded Test
D Idle Test With Loaded Preconditioning
State I/M Programs should test affected SUBARU AWD models using
any other EPA-91 approved performance warranty short test.
SUBARU models equipped with the AWD feature should be tested on a
four-wheel drive dynamometer or the State I/M Program may elect to use
a "double two-wheel dynamometer" arrangement. Under no circum-
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