catalytic converter JEEP GRAND CHEROKEE 2007 WK / 3.G Owners Manual

engine start. If the bulb does not come on when turning
the key from OFF to ON, have the condition checked
promptly.
Certain conditions such as a loose or missing gas cap,
poor fuel quality, etc. may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several of your typical driving cycles. In
most situations the vehicle will drive normally and will
not require towing.
The Malfunction Indicator Light flashes to alert you to
serious conditions that could lead to immediate loss of
power or severe catalytic converter damage. The vehicle
should be serviced as soon as possible if this occurs.
6. Airbag Warning Light
This light turns on and remains on for 6 to 8
seconds as a bulb check when the ignition
switch is first turned ON. If the light is not onduring starting, stays on, or turns on while driving, have
the system inspected by an authorized dealer as soon as
possible.
7. Anti-Lock Brake Warning Light
This light monitors the Anti-Lock Brake System.
The light will turn on when the ignition switch is
turned to the ON position and may stay on for as long as
four seconds.
If the ABS light remains on or turns on while driving, it
indicates that the Anti-Lock portion of the brake system
is not functioning and that service is required. However,
the conventional brake system will continue to operate
normally if the BRAKE warning light is not on.
If the ABS light is on, the brake system should be serviced
as soon as possible to restore the benefits of Anti-Lock
brakes. If the ABS light does not turn on when the
Ignition switch is turned to the ON position, have the
light inspected by an authorized dealer.
176 UNDERSTANDING YOUR INSTRUMENT PANEL

It is even more important to look for gasolines without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California reformu-
lated gasoline.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
conditions and would result in additional cost. Therefore
you should not have to add anything to the fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gas is prohibited by Federal law.
Using leaded gasoline can impair engine performance,
damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your dealer for service assistance.
•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
308 STARTING AND OPERATING

MAINTAINING YOUR VEHICLE
CONTENTS

Engine Compartment – 3.7L...............354

Engine Compartment – 4.7L...............355

Engine Compartment – 5.7L...............356

Engine Compartment – 3.0L Diesel..........357

Onboard Diagnostic System — OBD II........358
▫Loose Fuel Filler Cap Message............358

Emissions Inspection And Maintenance
Programs............................359

Replacement Parts......................361
Dealer Service.........................361

Maintenance Procedures..................362
▫Engine Oil..........................362
▫Drive Belts — Check Condition And Tension . . 366
▫Spark Plugs.........................367
▫Spark Plug Wires.....................367
▫Engine Air Cleaner Filter................367
▫Catalytic Converter....................368
▫Crankcase Emission Control System........369
7

Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
converter as an emission control device.
Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.CAUTION!
Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
368 MAINTAINING YOUR VEHICLE

WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your ex-
haust system. Do not park or operate your vehicle in
areas where your exhaust system can contact any-
thing that can burn.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may suggest severe
and abnormal catalyst overheating. If this occurs, stop
the vehicle, turn off the engine and allow it to cool.
Service, including a tune up to manufacturer’s specifica-
tions, should be obtained immediately.
To minimize the possibility of catalytic converter dam-
age:
•Do not shut off the engine or interrupt the ignition
when the transmission is in gear and the vehicle is in
motion.
•Do not try to start the engine by pushing or towing the
vehicle.
•Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idle or malfunctioning operating conditions.
Crankcase Emission Control System
Proper operation of this system depends on freedom
from sticking or plugging due to deposits. As vehicle
mileage builds up, the PCV valve and passages may
accumulate deposits. If a valve is not working properly,
replace it with a new valve. DO NOT ATTEMPT TO
CLEAN THE OLD PCV VALVE!
MAINTAINING YOUR VEHICLE 369
7

CargoLight ............................ 159
Cargo Load Floor........................ 163
Cargo Tie-Downs........................ 161
Catalytic Converter...................... 368
Caution, Exhaust Gas..................... 147
CD (Compact Disc) Player...............199,213
Cellular Phone.......................... 77
Center High Mounted Stop Light............ 406
Certification Label....................... 316
Chains, Tire............................ 294
Changing A Flat Tire..................... 339
Chart, Tire Sizing........................ 280
Checks, Safety......................... 65,66
Child Restraint...................... 54,60,62
Child Restraint Tether Anchors............. 58,60
Child Safety Locks........................ 28
Climate Control......................... 233
Clock ...........................201,215,221
Compact Disc (CD) Maintenance............. 232Compass.............................. 191
Compass Variance....................... 196
Computer, Trip/Travel.................... 191
Console, Overhead....................... 145
Contract, Service........................ 446
Converter, Catalytic...................... 368
Cooling System......................... 376
Adding Coolant (Antifreeze).............. 378
Coolant Capacity...................... 407
Coolant Level......................... 380
Disposal of Used Coolant................ 380
Drain, Flush, and Refill.................. 377
Inspection........................... 376
Points to Remember.................... 380
Pressure Cap......................... 379
Radiator Cap......................... 379
Selection of Coolant (Antifreeze).........377,407
Crankcase Emission Control System.......... 369
Cruise Control (Speed Control).............. 126
454 INDEX