2003 SUBARU IMPREZA service

Climate control
4-12
Cooling and dehumidifying in high humidity and low temperatureweather conditions
Under certain weather conditions (high relative hu-
midity, low temperatures, etc.) a small amount of wa-
ter vapor emission from the air outlets may be not-
iced. This condition is normal and does not indicate
any problem with the air conditioning system. Air conditioner compressor shut-off when engine is heavily loaded
To improve acceleration and gas mileage, the air
conditioner compressor is designed to temporarily
shut off during air conditioner operation whenever
the accelerator is fully depressed such as duringrapid acceleration or when driving on a steepupgrade. Refrigerant for your climate control system
Your air conditioner uses ozone friendly refrigerant
HFC134a. Therefore, the method of adding, chang-
ing or checking the refrigerant is different from the
method for CFC12 (Freon). Consult your SUBARU
dealer for service. Repairs needed as a result of using the wrong refrigerant are not covered under
warranty.

Starting and operating
7-2
Fuel
CAUTION
Use of a fuel which is low in quality or use of an inappropriate fuel additive may cause en- gine damage.
Fuel requirements
2.5 Liter models
The 2.5 Liter engine is designed to operate using
unleaded gasoline with an octane rating of 87 AKI or
higher.
2.0 Liter (turbo) models
The 2.0 Liter turbo engine is designed to operate
using premium unleaded gasoline with an octane
rating of 91 AKI or higher. If premium unleaded gas-
oline is not available, regular unleaded gasoline with an octane rating of 87 AKI or higher may be tempo-
rarily used. For optimum engine performance and
driveability, it is recommended that you use pre-
mium grade unleaded gasoline.
Fuel octane rating
This octane rating is the average of the ResearchOctane and Motor Octane numbers and is com-
monly referred to as the Anti Knock Index (AKI).Using a gasoline with a lower octane rating cancause persistent and heavy knocking, which can
damage the engine. Do not be concerned if your
vehicle sometimes knocks lightly when you drive up a hill or when you accelerate. See your dealer or a
qualified service technician if you use a fuel with thespecified octane rating and your vehicle knocks
heavily or persistently.
Unleaded gasoline
The neck of the fuel filler pipe is designed to acceptonly an unleaded gasoline filler nozzle. Under no
circumstances should leaded gasoline be used be-
cause it will damage the emission control system
and may impair driveability and fuel economy.
Gasoline for California-certified LEV
Your vehicle was certified to California ’s low emis-
sion vehicle (LEV) standards as indicated on the
underhood tune-up label. It is designed to optimize
engine and emission performance with gasoline that
meets the clean burning low-sulfur California gaso-
line specifications. If you live in any other state than
California, your vehicle will operate on gasoline

Starting and operating
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meeting Federal specifications. Gasoline sold out-
side California is permitted to have higher sulfur lev-
els, which may affect the performance of your ve-
hicle’s catalytic converter and may produce a sulfur
exhaust odor or smell. SUBARU recommends that
you try a different brand of unleaded gasoline hav-
ing lower sulfur to determine if the problem is fuel
related before returning your vehicle to an autho-rized dealer for service.
Gasoline for cleaner air
Your use of gasoline with detergent additives will
help prevent deposits from forming in your engine
and fuel system. This helps keep your engine in
tune and your emission control system working
properly, and is a way of doing your part for cleaner
air. If you continuously use a high quality fuel with
the proper detergent and other additives, youshould never need to add any fuel system cleaning agents to your fuel tank.
Many gasolines are now blended with materials
called oxygenates. Use of these fuels can also help
keep the air cleaner. Oxygenated blend fuels, such
as MTBE (Methyl Tertiary Butyl ether) or ethanol
(ethyl or grain alcohol) may be used in your vehicle,
but should contain no more than 15% MTBE or 10%
ethanol for the proper operation of your SUBARU. In addition, some gasoline suppliers are now pro-
ducing reformulated gasolines, which are designed
to reduce vehicle emissions. SUBARU approves the
use of reformulated gasoline.
If you are not sure what the fuel contains, you should
ask your service station operators if their gasolines
contain detergents and oxygenates and if they have
been reformulated to reduce vehicle emissions.
As additional guidance, only use fuels suited for
your vehicle as explained below.
Fuel should be unleaded and have an octane rat-
ing no lower than that specified in this manual. Methanol (methyl or wood alcohol) is sometimes
mixed with unleaded gasoline. Methanol can beused in your vehicle ONLY if it does not exceed 5%
of the fuel mixture AND if it is accompanied by suffi-
cient quantities of the proper cosolvents and corro-
sion inhibitors required to prevent damage to the
fuel system. Do not use fuel containing methanolEXCEPT under these conditions.
If undesirable driveability problems are experi-
enced and you suspect they may be fuel related, try
a different brand of gasoline before seeking service
at your SUBARU dealer. Fuel system damage or driveability problems
which result from the use of improper fuel are not

Starting and operating
7-6
Do not let fuel spill on the exterior surfaces
of the vehicle. Fuels may cause paint damage, which is not
covered under the SUBARU Limited Warranty. Always use a genuine SUBARU fuel filler
cap. If you use the wrong cap, it may not fit or have proper venting, and your fuel tank and
emission control system might be damaged. State emission testing (U.S. only) At state inspection time, remember to tell your inspection or service station in advance not to
place your Subaru AWD vehicle on a two-wheel
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 onthe 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 prob-
lems are required to adopt an enhanced vehicleemission 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)

Starting and operating
7-8
mination is observed, there is no stored diagnostic
trouble codes, and the OBD system readiness moni-
tors 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 readi- ness monitors “Not Ready ” is greater than three.
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-in-spection. Owners of rejected or failing vehicles should con-
tact their Subaru Dealer for service. Preparing to drive
You should perform the following checks and adjust-
ments every day before you start driving.
1. Check that all windows, mirrors, and lights are
clean and unobstructed.
2. Check the appearance and condition of the tires.
Also check tires for proper inflation.
3. Look under the vehicle for any sign of leaks.
4. Check that the hood, trunk and rear gate are fullyclosed.
5. Check the adjustment of the seat.
6. Check the adjustment of the inside and outside
mirrors.
7. Fasten your seatbelt. Check that your passen-gers have fastened their seatbelts.
8. Check the operation of the warning and indicator
lights when the ignition switch is turned to the
“ON”
position.
9. Check the gauges, indicator and warning lights
after starting the engine. NOTE Engine oil, engine coolant, brake fluid, washer
fluid and other fluid levels should be checked
daily, weekly or at fuel stops.

Driving tips
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Never turn off the ignition switch while the vehicle
is moving. Keep your engine tuned-up. If you feel the engine
running rough (misfiring, backfiring or incomplete
combustion), have your vehicle checked and re-
paired by an authorized SUBARU dealer. Do not apply undercoating or rust prevention
treatment to the heat shield of catalytic converter and the exhaust system.
WARNING
Avoid fire hazards. Do not drive or park the
vehicle anywhere near flammable materials
(e.g. grass, paper, rags or leaves), becausethe catalytic converter operates at very hightemperatures. Keep everyone and flammable materials
away from the exhaust pipe while the engine is running. The exhaust gas is very hot. Periodic inspections
To keep your vehicle in the best condition at all
times, always have the recommended maintenance
services listed in the maintenance schedule in the“
Warranty and Maintenance Booklet ” performed at
the specified time or mileage intervals.

Driving tips
8-35
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eral, state/province and/or other applicable regula- tions.
Trailer lights
Connection of trailer lights to your vehicle ’s electrical
system requires modifications to the vehicle ’s light-
ing circuit to increase its capacity and accommo-
date wiring changes. To ensure the trailer lights are
connected properly, please consult your SUBARU
dealer. Check for proper operation of the turn sig-nals, the brake lights and parking lights each timeyou hitch up.
CAUTION
Direct splicing or other improper connection
of trailer lights may damage your vehicle ’s
electrical system and cause a malfunction ofyour vehicle ’s lighting system.
Tires
Make sure that all the tires on your vehicle are prop-
erly inflated to the pressure specified on the tire
placard located on the left center pillar of your ve-hicle.
Trailer tire condition, size, load rating and proper
inflation pressure should be in accordance with the trailer manufacturer
’s specifications.
In the event your vehicle gets a flat tire when towing
a trailer, ask a commercial road service to repair the
flat tire.
If you carry a regular size spare tire in your vehicle
or trailer as a precaution against getting a flat tire,
be sure that the spare tire is firmly secured.
WARNING
Never tow a trailer when the temporary spare tire is used. The temporary spare tire is not
designed to sustain the towing load. Use ofthe temporary spare tire when towing canresult in failure of the spare tire and/or less
stability of the vehicle.
Trailer towing tips
CAUTION
Never exceed 45 mph (72 km/h) when tow-
ing a trailer in hilly country on hot days. When towing a trailer, steering, stability,
stopping distance and braking performancewill be different from normal operation. For

In case of emergency
9-13
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the wheel nuts to the specified torque, following the
tightening order in the illustration.
The torque for tightening the nuts is 58 to 72 ft-lb (80
to 100 N-m, 8 to 10 kg-m). This torque is equivalentto applying about 88 to 110 lbs (40 to 50 kg) at the
top of the wheel nut wrench. Never use your foot on
the wheel nut wrench or a pipe extension on the
wrench because you may exceed the specified
torque. Have the wheel nut torque checked at the
nearest automotive service facility.
15. Store the flat tire in the spare tire compartment.
Put the spacer and tighten the attaching bolt firmly.
Also store the jack and wheel nut wrench in theirstorage locations.
After placing the jack in its storage location, turn the
jackscrew clockwise by hand until it becomes too
hard to turn. Then, tighten it by an additional 1/4 –
1/3 of a turn using a screwdriver or the jack handle.
Unless the jack is properly secured, it may rattlewhile the vehicle is moving.