2003 SUBARU IMPREZA check engine

Driving tips
8-5
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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
8-9
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aid kit and portable phone or citizens band radio. Drive carefully. Do not take unnecessary risks by
driving in dangerous areas or over rough terrain. Slow down and employ extra caution at all times.
When driving off-road, you will not have the benefit
of marked traffic lanes, banked curves, traffic signs and the like. Do not drive across steep slopes. Instead, drive
either straight up or straight down the slopes. A ve-
hicle can much more easily tip over sideways than it
can end over end. Avoid driving straight up or down
slopes that are too steep. Avoid sharp turning maneuvers, especially at
higher speeds. Do not grip the inside or spokes of the steering
wheel. A bad bump could jerk the wheel and injureyour hands. Instead drive with your fingers andthumbs on the outside of the rim. If driving through water, such as when crossing
shallow streams, first check the depth of the water
and the bottom of the stream bed for firmness and
ensure that the bed of the stream is flat. Drive slowly
and completely through the stream. The water
should be shallow enough that it does not reach the
vehicle’ s undercarriage. Water entering the engine
air intake or the exhaust pipe or water splashing
onto electrical parts may damage your vehicle and may cause it to stall. Never attempt to drive through
rushing water; regardless of its depth, it can wash
away the ground from under your tires, resulting in
possible loss of traction and even vehicle rollover.
Always check your brakes for effectiveness im-
mediately after driving in sand, mud or water. Do
this by driving slowly and stepping on the brake
pedal. Repeat that process several times to dry outthe brake discs and brake pads. Do not drive or park over or near flammable mate-
rials such as dry grass or fallen leaves, as they may
burn easily. The exhaust system is very hot while the
engine is running and right after the engine stops.
This could create a fire hazard. After driving through tall grass, mud, rock, sand,
rivers, etc., check that there is no grass, bush, pa-
per, rags, stones, sand, etc. adhering to or trapped
on the underbody. Clear off any such matter from
the underbody. If the vehicle is used with these ma-
terials trapped or adhering to the underbody, a
mechanical breakdown or fire could occur. Secure all cargo carried inside the vehicle and
make certain that it is not piled higher than the seat-
backs. During sudden stops or jolts, unsecured car-
go could be thrown around in the vehicle and cause
injury. Do not pile heavy loads on the roof. Thoseloads raise the vehicle ’s center of gravity and make

Driving tips
8-10
it more prone to tip over. If you must rock the vehicle to free it from sand or
mud, depress the accelerator pedal slightly and
move the selector lever back and forth between “D”
and “R” repeatedly. Do not race the engine. For the
best possible traction, avoid spinning the wheels
when trying to free the vehicle.
When the road surface is extremely slippery, you
can obtain better traction by starting the vehicle withthe transmission in 2nd than 1st (both for MT and
AT). Never equip your vehicle with tires larger than
those specified in this manual. Frequent driving of an AWD vehicle under hard-
driving conditions such as rough roads or off roads
will necessitate more frequent replacement of engine
oil, brake fluid and transmission oil than that specified
in the maintenance schedule described in the “War -
ranty and Maintenance Booklet ”.
Remember that damage done to your Subaru while
operating it off-road and not using common sense
precautions such as those listed above is not eligi-ble for warranty coverage. Winter driving

Operation during cold weather
Carry some emergency equipment, such as tire
chains, a window scraper, a bag of sand, flares, a small shovel, and jumper cables.
Check the battery and cables. Cold temperatures
reduce battery capacity. The battery must be in
good condition to provide enough power for cold
winter starts.
Use an engine oil of proper grade and viscosity for

Driving tips
8-11
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cold weather. Heavy summer oil will cause harder
starting.
Keep the door locks from freezing by squirting themwith deicer or glycerin.
Forcing a frozen door open may damage or sepa-
rate the rubber weather strips around the door. If the
door is frozen, use hot water to melt the ice, and af-
terwards thoroughly wipe the water away. Use a windshield washer fluid that contains an anti-
freeze solution. Do not use engine antifreeze or oth-
er substitutes because they may damage the paint of the vehicle.
Before driving your vehicle
Before entering the vehicle, remove any snow or ice
from your shoes because that could make the ped-
als slippery and dangerous.
While warming up the vehicle before driving, check that the accelerator pedal, brake pedal, and all oth-
er controls operate smoothly. Clear away ice and snow that has accumulated un-
der the fenders to avoid making steering difficult.
During severe winter driving, stop when and where it is safe to do so and check under the fenders peri-
odically.
Parking in cold weather
Do not use the parking brake when parking for long
periods in cold weather since it could freeze in that
position. Instead, observe the following:
1. Place the shift lever in “1” or “R” for manual trans-
mission vehicles, and in “P” for automatic transmis-
sion vehicles.
2. Use tire stops under the tires to prevent the ve-
hicle from moving.
When the vehicle is parked in snow or when it
snows, raise the wiper blades off the glass to pre-vent damage to them.
When the vehicle has been left parked after use on
roads heavily covered with snow, or has been left
parked during a snowstorm, icing may develop onthe brake system, which could cause poor braking
action. Check for snow or ice buildup on the sus-
pension, disc brakes and brake hoses underneath the vehicle.
If there is caked snow or ice, remove it, being care-ful not to damage the disc brakes and brake hoses
and ABS harness.

Driving tips
8-27
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Trailer towing
Your car is designed and intended to be used pri-
marily as a passenger-carrying vehicle. Towing a
trailer puts additional loads on your car ’s engine, dri-
vetrain, brakes, tires and suspension and has an
adverse effect on fuel economy.
If you do decide to tow a trailer, your safety and sat-
isfaction depend upon proper use of correct equip-
ment and cautious operation of your vehicle. Seekthe advice of your SUBARU dealer to assist you in
purchasing a hitch and other necessary towing
equipment appropriate for your vehicle. In addition,
be sure to follow the instructions on correct installa-
tion and use provided by the trailer and other towing
equipment manufacturers.
SUBARU assumes no responsibility for injuries or
vehicle damage that result from trailer towing equip-
ment, or from any errors or omissions in the instruc- tions accompanying such equipment or for your fail-
ure to follow the proper instructions. Warranties and maintenance
SUBARU warranties do not apply to vehicle damage or malfunction caused by trailer towing. If you use
your vehicle to tow a trailer, more frequent mainte-
nance will be required due to the additional load. (Refer to
“Maintenance schedule under severe driv-
ing conditions ” in the “Warranty and Maintenance
Booklet”.)
Under no circumstances should a trailer be towedwith a new vehicle or a vehicle with any new power-
train component (engine, transmission, differential, wheel bearings, etc.) for the first 1,000 miles (1,600 km) of driving. Maximum load limits
WARNING
Never exceed the maximum load limits ex-
plained below. Exceeding the maximum loadlimits could cause personal injury and/or ve-hicle damage.
CAUTION
Adequate size trailer brakes are required
when the trailer and its cargo exceed 1,000 lbs (453 kg) total weight. Before towing a trailer, check the trailer total
weight, GVW, GAWs and tongue load. Make sure the load and its distribution in your
vehicle and trailer are acceptable.

Driving tips
8-36
safety’s sake, you should employ extra cau-
tion when towing a trailer and you should
never speed. You should also keep the follow-ing tips in mind:
Before starting out on a trip
Check that the vehicle and vehicle-to-hitch mount-
ing are in good condition. If any problems are
apparent, do not tow the trailer. Check that the vehicle sits horizontally with the
trailer attached. If the vehicle is tipped sharply up at
the front and down at the rear, check the total trailer
weight, GVW, GAWs and tongue load again, then
confirm that the load and its distribution are accept-able. Check that the tire pressures are correct.
Check that the vehicle and trailer are connected
properly. Confirm that
–the trailer tongue is connected properly to the
hitch ball.– the trailer lights connector is connected prop-
erly and trailer ’s brake lights illuminate when the
vehicle’ s brake pedal is pressed, and that the trail-
er’ s turn signal lights flash when the vehicle ’s turn
signal lever is operated.– the safety chains are connected properly. –
all cargo in the trailer is secured safety in posi-
tion.– the side mirrors provide a good rearward field of
view without a significant blind spot.
Sufficient time should be taken to learn the “feel”
of the vehicle/trailer combination before starting out
on a trip. In an area free of traffic, practice turning, stopping and backing up.
Driving with a trailer
You should allow for considerably more stopping
distance when towing a trailer. Avoid sudden brak-
ing because it may result in skidding or jackknifing
and loss of control. Avoid abrupt starts and sudden accelerations. If
your vehicle has a manual transmission, always start
out in first gear and release the clutch at moderate
engine revolution. Avoid uneven steering, sharp turns and rapid lane
changes. Slow down before turning. Make a longer than
normal turning radius because the trailer wheels will
be closer than the vehicle wheels to the inside of the
turn. In a tight turn, the trailer could hit your vehicle. Crosswinds will adversely affect the handling of
your vehicle and trailer, causing sway. Crosswindscan be due to weather conditions or the passing of

In case of emergency
9-18
Confirm that the cooling fan is turning. If the fan is
not turning, immediately turn the engine off and con-
tact your authorized dealer for repair.
3. After the engine coolant temperature has
dropped, turn off the engine.
If the temperature gauge stays at the overheated
zone, turn the engine off.
4. After the engine has fully cooled down, check the
coolant level in the reserve tank.If the coolant level is below the “LOW” mark, add
coolant up to the “FULL” mark.
5. If there is no coolant in the reserve tank, add
coolant to the reserve tank. Then remove the radia- tor cap and fill the radiator with coolant.
If you remove the radiator cap from a hot radiator,
first wrap a thick cloth around the radiator cap, then
turn the cap counterclockwise slowly without press-
ing down until it stops. Release the pressure from
the radiator. After the pressure has been fully re-
leased, remove the cap by pressing down and turn-ing it. Towing
If towing is necessary, it is best done by your
SUBARU dealer or a commercial towing service.
Observe the following procedures for safety.
WARNING
Never tow AWD vehicles (both AT and MT) with the front wheels raised off the groundwhile the rear wheels are on the ground, orwith the rear wheels raised off the groundwhile the front wheels are on the ground. This

11
11-1
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Maintenance schedule 11-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance precautions 11-3 . . . . . . . . . . . . . . . . . . . . . . . .
Engine hood 11-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment overview 11-8 . . . . . . . . . . . . . . . . .
2.5 liter model 11-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 liter (Turbo) model 11-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the oil and oil filter 11-11 . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-13 . . . . . . . . . . .
Recommended grade and viscosity under
severe driving conditions 11-15 . . . . . . . . . . . . . . . . . . . . . .
Synthetic oil 11-15
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 11-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan, hose and connections 11-16 . . . . . . . . . . . .
Engine coolant 11-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air cleaner element 11-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the air cleaner element 11-20 . . . . . . . . . . . . . .
Spark plugs 11-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended spark plugs 11-24 . . . . . . . . . . . . . . . . . . . . .
Drive belts 11-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual transmission oil 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-26 . . . . . . . . . . .
Automatic transmission fluid 11-27 . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-27 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front differential gear oil (AT vehicles) 11-29
. . . . .
Checking the oil level 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-30 . . . . . . . . . . .
Rear differential gear oil 11-31 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the gear oil level 11-31 . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-32 . . . . . . . . . . .
Power steering fluid 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . .
Clutch fluid (MT vehicles) 11-35 . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended clutch fluid 11-36 . . . . . . . . . . . . . . . . . . . . . .
Brake booster 11-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal 11-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the brake pedal free play 11-37 . . . . . . . . . . . .
Checking the brake pedal reserve distance 11-37 . .
Clutch pedal (MT vehicles) 11-38 . . . . . . . . . . . . . . . . . . . . . .
Checking the clutch function 11-38 . . . . . . . . . . . . . . . . . . . .
Checking the clutch pedal free play 11-38 . . . . . . . . . . .
Replacement of brake pad and lining 11-39 . . . . . . . .
Breaking-in of new brake pads and linings 11-39 . . .
Parking brake stroke 11-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires and wheels 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types of tires 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance and service