catalytic converter SUBARU IMPREZA 2007 3.G Owners Manual

7-2Starting and operating
Fuel
CAUTION
Use of a fuel which is low in quality
or use of an inappropriate fuel
additive may cause engine damage.
& Fuel requirements
! 2.5-liter non-turbo models
The 2.5-liter non-turbo engine is designed
to operate using unleaded gasoline with
an octane rating of 87 AKI or higher. ! WRX
The 2.5-liter turbo engine is designed to
operate using premium unleaded gasoline
with an octane rating of 91 AKI or higher. If
premium unleaded gasoline is not avail-
able, regular unleaded gasoline with an
octane rating of 87 AKI or higher may be
temporarily used. For optimum engine
performance and driveability, it is required
that you use premium grade unleadedgasoline. NOTE
Be sure to use premium unleaded
gasoline of 91 AKI or higher for WRX.
If other gasoline (lower than 91 AKI) is used, knocking, reduced output and
poor accelerator response will result. !
WRX-STI
The 2.5-liter turbo engine is designed to
operate using super-premium unleaded
gasoline with an octane rating of 93 AKI or
higher. If super-premium unleaded gaso-
line with an octane rating of 93 AKI or
higher is not available, premium unleaded
gasoline with an octane rating of 91 AKI or
higher may be temporarily used. For
optimum engine performance and drive-
ability, it is required that you use super-
premium grade unleaded gasoline with an
octane rating of 93 AKI or higher.
NOTE
Be sure to use super-premium un-
leaded gasoline of 93 AKI or higher
for WRX-STI. If other gasoline (lower
than 93 AKI) is used, knocking, re-
duced output and poor accelerator
response will result. ! Fuel octane rating
This octane rating is the average of the
Research Octane and Motor Octane
numbers and is commonly referred to as
the Anti Knock Index (AKI).
Using a gasoline with a lower octane
rating can cause 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 the specified octane
rating and your vehicle knocks heavily or
persistently. !
Unleaded gasoline
The neck of the fuel filler pipe is designed
to accept only an unleaded gasoline filler
nozzle. Under no circumstances should
leaded gasoline be used because it will
damage the emission control system and
may impair driveability and fuel economy. ! Gasoline for California-certified LEV
If your vehicle was certified to California ’s
low emission 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 Cali-
fornia gasoline specifications. If you live in
any other state than California, your
vehicle will operate on gasoline meeting
Federal specifications. Gasoline sold out-
side California is permitted to have higher
sulfur levels, which may affect the perfor-
mance of your vehicle ’s catalytic converter
and may produce a sulfur exhaust odor or

New vehicle break-in driving–the first
1,000 miles (1,600 km) ..................................... 8-2
Fuel economy hints ............................................ 8-2
Engine exhaust gas (Carbon monoxide) ........... 8-2
Catalytic converter .............................................. 8-3
Periodic inspections ........................................... 8-4
Driving in foreign countries ............................... 8-4
Driving tips for AWD vehicles ............................ 8-5
Off road driving ................................................... 8-6
All AWD models except OUTBACK SPORT .......... 8-6
OUTBACK SPORT ............................................... 8-6
Winter driving ...................................................... 8-8
Operation during cold weather ............................. 8-8
Driving on snowy and icy roads .......................... 8-9
Corrosion protection .......................................... 8-10
Snow tires ......................................................... 8-10
Tire chains ......................................................... 8-11 Rocking the vehicle
........................................... 8-12
Loading your vehicle ......................................... 8-12
Vehicle capacity weight ...................................... 8-13
GVWR and GAWR (Gross Vehicle Weight Rating and Gross Axle Weight Rating) ........................ 8-14
Roof rail and crossbar (if equipped) ................... 8-14
Trailer hitch (if equipped) .................................. 8-17
Connecting a trailer ........................................... 8-18
When you do not tow a trailer .. .......................... 8-19
Trailer towing ..................................................... 8-20
Warranties and maintenance .............................. 8-20
Maximum load limits .......................................... 8-20
Trailer hitches .................................................... 8-23
Connecting a trailer ........................................... 8-24
Trailer towing tips .............................................. 8-25
STI front lip spoiler (if equipped) ...................... 8-28Driving tips
8

exhaust fumes are entering the
vehicle, have the problem
checked and corrected as soon
as possible. If you must drive
under these conditions, drive
only with all windows fully open.
. Keep the trunk lid (Sedan) or rear
gate (Wagon) closed while driv-
ing to prevent exhaust gas from
entering the vehicle.
NOTE
Due to the expansion and contraction
of the metals used in the manufacture
of the exhaust system, you may hear a
crackling sound coming from the ex-
haust system for a short time after the
engine has been shut off. This sound isnormal. Catalytic converter
Turbo models
Non-turbo models
The catalytic converter is installed in the
exhaust system. It serves as catalyst to reduce HC, CO and NOx in exhaust
gases, thus providing cleaner exhaust.
To avoid damage to the catalytic conver- ter: .
Use only unleaded fuel. Even a small
amount of leaded fuel will damage the
catalytic converter. . Never start the engine by pushing or
pulling the vehicle.. Avoid racing the engine.
. Never turn off the ignition switch while
the vehicle is moving.. Keep your engine tuned-up. If you feel
the engine running rough (misfiring, back-
firing or incomplete combustion), have
your vehicle checked and repaired by an
authorized SUBARU dealer. . Do not apply undercoating or rust
prevention treatment to the heat shield of
catalytic converter and the exhaust sys-tem.
WARNING
. Avoid fire hazards. Do not drive
or park the vehicle anywhere
near flammable materials (e.g.
grass, paper, rags or leaves),
because the catalytic converter
operates at very high tempera-tures. Driving tips
8-3
– CONTINUED –

14-2Index
A
ABS (Anti-lock Brake System) ..................................... 7-21
Warning light ................................................. 3-17, 7-22
Accessories ....................................................... 5-2, 11-44
Accessory power outlet ................................................. 6-6
Active head restraint ..................................................... 1-4
Air cleaner element ................................................... 11-15
Air conditioner ............................................................. 4-7
Air filtration system ..................................................... 4-12
Air flow selection .......................................................... 4-2
Alarm system ............................................................ 2-13
All-Wheel Drive warning light (AT vehicles) .................... 3-19
Aluminum wheels ...................................................... 11-35
Antenna system ........................................................... 5-2
Anti-lock Brake System (ABS) ..................................... 7-21
Arming the system ..................................................... 2-14
Armrest ....................................................................... 1-7
Ashtray ....................................................................... 6-8
AT OIL TEMPerature warning light ............................... 3-17
Audio set .................................................................... 5-3
Auto-dimming mirror/compass ...................................... 3-32
Automatic climate control system ................................... 4-8
Automatic transmission ............................................... 7-15
Capacities ............................................................. 12-4
Fluid .................................................................... 11-20
Selector lever ........................................................ 7-16
Temperature warning light (AT OIL TEMP) ................. 3-17
Automatic/Emergency Locking Retractor (A/ELR) ... ........ 1-11BBattery
.................................................................... 11-41
Jump starting .......................................................... 9-8
Replacement (Remote keyless entry system) .............. 2-7
Brake Booster ............................................................... 11-27
Fluid ................................................................... 11-25
Pad and lining ...................................................... 11-29
Parking ....................................................... 7-24, 11-30
Pedal .................................................................. 11-27
System .................................................................. 7-21
Brake pedal Free play ............................................................. 11-27
Reserve distance .................................................. 11-28
Brake system ............................................................. 7-21
Warning light .......................................................... 3-18
Braking ..................................................................... 7-20
Tips ...................................................................... 7-20
Breaking-in of new brake pads and linings ................... 11-29
Bulb Chart .................................................................... 12-9
Replacing ............................................................ 11-45
C Capacities ................................................................. 12-4
Cargo area Bars ...................................................................... 6-12
Cover .................................................................... 6-10
Light ...................................................................... 6-2
Tie-down hooks ...................................................... 6-11
Catalytic converter ....................................................... 8-3