2002 JEEP LIBERTY Workshop Manual

DIAGNOSIS AND TESTING - EXHAUST SYSTEM
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts to specified
torque at leaking joints.
2. Rusted or blown out muffler. 2. Replace muffler. Inspect exhaust
system.
3. Broken or rusted out exhaust
pipe.3. Replace exhaust pipe.
4. Exhaust pipe leaking at manifold
flange.4. Tighten/replace flange attaching
nuts/bolts.
5. Exhaust manifold cracked or
broken.5. Replace exhaust manifold.
6. Leak between exhaust manifold
and cylinder head.6. Tighten exhaust manifold to
cylinder head bolts.
7. Catalytic converter rusted or
blown out.7. Replace catalytic converter assy.
8. Restriction in exhaust system. 8. Remove restriction, if possible.
Replace restricted part if necessary.
CAUTION:
When servicing and replacing exhaust system components, disconnect the oxygen sensor connector(s). Allowing
the exhaust to hang by the oxygen sensor wires will damage the harness and/or sensor.
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
CAUTION: DO NOT remove spark plug wires from
plugs or by any other means short out cylinders.
Failure of the catalytic converter can occur due to a
temperature increase caused by unburned fuel
passing through the converter.
The stainless steel catalytic converter body is
designed to last the life of the vehicle. Excessive heat
can result in bulging or other distortion, but exces-
sive heat will not be the fault of the converter. If
unburned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct thecause of the damage at the same time the converter
is replaced. Also, inspect all other components of the
exhaust system for heat damage.
Unleaded gasoline must be used to avoid con-
taminating the catalyst core.
50 State emission vehicles incorporate two mini
catalytic converters located after the exhaust mani-
folds and before the inline catalytic converter.
REMOVAL
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove the bolts from the crossover pipe to the
catalytic converter connection.
(4) Disconnect oxygen sensor wiring.
(5) Loosen and remove the nuts from the clamp
that hold the catalytic converter to the exhaust pipe
flange connection.
11s - 2 EXHAUST SYSTEMKJ
EXHAUST SYSTEM (Continued)

2.4L ENGINES
(1) Disconnect the oxygen sensors.
(2) Remove the two bolts and flanged nuts at the
manifold (Fig. 1).
(3) Lower the catalyst assembly and slide out of
the mount at the transmission (if equipped).
(4) Remove the catalyst assembly from the vehicle.
3.7L ENGINES
NOTE: Do not remove nut from T-Bolt. Only remove
nut far enough, so that the T end can be removed
from the clamp.
(1) Remove the T bolt end of the fastener, from the
clamp.
(2) Spread the clamp, and remove the catalytic
converter from the vehicle.
(3) Discard the clamp (Fig. 2).
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
(1) Position the catalytic converter onto the
exhaust pipe flange connection. Tighten the nuts to
28 N´m (250 in. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install the exhaust clamp at the muffler and
catalytic converter connection. Tighten the clamp
nuts to 47 N´m (35 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
Fig. 1 2.4L CATALYST ASSEMBLY - 4x4
1- FLANGED NUT
2- CATALYST ASSEMBLY
3- BOLT
4- HANGER
5- NUT
Fig. 2 Catalyst Removal
1 - V-Clamp
2 - Catalytic Converter
3 - Flange
4 - Crossover Pipe
5 - T-Bolt
KJEXHAUST SYSTEM 11s - 3
CATALYTIC CONVERTER (Continued)

CROSS-OVER PIPE
REMOVAL
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with lubricant.
Allow 5 minutes for penetration.
(3) Remove the retaining fasteners holding cross-
over pipe to exhaust pipe.
(4) Remove the fasteners from the crossover pipe
to the catalytic converter connection.
(5) Remove the crossove pipe from the hanger
insulator (Fig. 3).
INSTALLATION
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
(1) Install the crossove pipe into the hanger insu-
lator.
(2) Install and torque the fasteners in the cross-
over pipe to the left and right catalytic converter con-
nection.
(3) Install and torque the retaining fasteners hold-
ing the crossover pipe to exhaust pipe.
(4) Lower vehicle..
(5) Start engine and check for leaks.
HEAT SHIELDS
DESCRIPTION
Heat shields (Fig. 4) are needed to protect both the
vehicle and the environment from the high tempera-
tures developed by the catalytic converter. The cata-
lytic converter releases additional heat into the
exhaust system. Under severe operating conditions,
the temperature increases in the area of the con-
verter. Such conditions can exist when the engine
misfires or otherwise does not operate at peak effi-
ciency.
MUFFLER
DESCRIPTION
The 2.4L and 3.7L engine uses a galvanized steel
muffler (Fig. 5) to control exhaust noise levels and
exhaust back pressure.
REMOVAL
All original equipment exhaust systems are manu-
factured with the exhaust tailpipe welded to the muf-
fler. Service replacement mufflers and exhaust
tailpipes are either clamped together or welded
together.Fig. 3 Crossover Pipe
1 - Crossover-toCatalytic Converter flange
2 - Crossover Pipe
3 - Crossover Pipe to Tail Pipe Flange
4 - Hanger Bracket
11s - 4 EXHAUST SYSTEMKJ

WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINE.
CAUTION: When servicing exhaust system compo-
nents, disconnect the oxygen sensor connector.
Allowing the exhaust system to hang by the oxygen
sensor harness will damage the wiring and/or sen-
sor.(1) Raise and support the vehicle.
(2) Disconnect front tailpipe hanger from the insu-
lator (Fig. 6).
(3) Remove the mounting nuts from the muffler to
catalytic converter flange (Fig. 6).
(4) Remove the tailpipe from the rear tailpipe
hanger.
(5) Remove the muffler and tailpipe assembly from
the vehicle (Fig. 6).
INSTALLATION
All original equipment exhaust systems are manu-
factured with the exhaust tailpipe welded to the muf-
fler. Service replacement mufflers and exhaust
tailpipes are either clamped together or welded
together.
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINE.
CAUTION: When servicing exhaust system compo-
nents, disconnect the oxygen sensor connector.
Allowing the exhaust system to hang by the oxygen
sensor harness will damage the wiring and/or sen-
sor.
Fig. 4 KJ REAR HEAT SHIELD
1 - HEAT SHIELD
2 - NUT
Fig. 5 Muffler - Typical
1 - MUFFLER
Fig. 6 KJ MUFFLER AND TAILPIPE ASSEMBLY
1- TAILPIPE HANGERS
2- MUFFLER
3- FLANGE
4- NUT
KJEXHAUST SYSTEM 11s - 5
MUFFLER (Continued)

(1) Position muffler and tailpipe assembly into
vehicle.
(2) Install clamp retaining tailpipe to the rear
tailpipe hanger.DO NOTtighten clamp at this time.
(3) Install mounting nuts onto the muffler to cata-
lytic converter flange studs.DO NOTtighten nuts at
this time.
(4) Make sure the exhaust system is in proper
alignment. There should be at least 25mm (1 inch)clearance between the exhaust components and any
surrounding components.
(5) Tighten muffler to catalytic converter flange
mounting nuts to 28.5 N´m (21 ft. lbs.).
(6) Tighten tailpipe clamp to 48 N´m (35 ft. lbs.).
11s - 6 EXHAUST SYSTEMKJ
MUFFLER (Continued)

FRAMES & BUMPERS
TABLE OF CONTENTS
page page
FRONT FASCIA
REMOVAL.............................1
INSTALLATION..........................2
REAR FASCIA
REMOVAL.............................2
INSTALLATION..........................2
REAR FASCIA SUPPORT
REMOVAL.............................3
INSTALLATION..........................3
FRAME
SPECIFICATIONS
SPECIFICATIONS - FRAME DIMENSIONS . . . 3
SPECIFICATIONS - TORQUE.............6
FRONT SKID PLATE
REMOVAL.............................6
INSTALLATION..........................6
ENGINE CRADLE CROSSMEMBER
REMOVAL.............................6
INSTALLATION..........................6TRANSFER CASE SKID PLATE
REMOVAL.............................7
INSTALLATION..........................7
REAR CROSSMEMBER
REMOVAL.............................7
INSTALLATION..........................7
FRONT TOW HOOK
REMOVAL.............................8
INSTALLATION..........................8
REAR TOW HOOK
REMOVAL.............................8
INSTALLATION..........................8
TRAILER HITCH
REMOVAL.............................9
INSTALLATION..........................9
FUEL TANK SKID PLATE
REMOVAL.............................9
INSTALLATION..........................9
FRONT FASCIA
REMOVAL
(1) Remove the grille. (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL)
(2) Raise and support vehicle.
(3) Remove the front wheel opening flare moldings.
(Refer to 23 - BODY/EXTERIOR/FRONT WHEEL
OPENING FLARE MOLDINGS - REMOVAL)
(4) Remove the four screws through the lower air
dam (Fig. 1).
(5) Disconnect the electrical connectors:
²Fascia to grille opening reinforcement. (Fig. 1)
²Side repeater lights, both sides, if equipped.
(Fig. 2)
(6) Remove the six push pins from the grill sup-
port.
(7) Remove the rivets attaching the air dam to the
wheelhouse splash shield.
(8) Release the support tabs beneath the head-
lamps.
(9) Release the inner support clips from within the
fascia between the lights (Fig. 2).
(10) Remove the fascia.
Fig. 1 FRONT FASCIA
1 - ELECTRICAL CONNECTOR
2 - PUSH PINS
3 - FRONT FASCIA ASSEMBLY
4 - LOWER SCREWS
5 - PLASTIC RIVETS (2)
6 - INNER SUPPORT CLIPS
7 - SUPPORT TABS
KJFRAMES & BUMPERS 13 - 1

INSTALLATION
(1) Install the fascia.
(2) Connect the electrical connectors.
²Side repeater lights, both sides, if equipped.
²Fascia to grille opening reinforcement.
(3) Install the six push pin fasteners into the grill
support.
(4) Install the four screws through the lower air
damn.
(5) Install new rivets attaching the air dam to the
wheelhouse splash shield.
(6) Install the front wheel opening flare moldings.
(Refer to 23 - BODY/EXTERIOR/WHEEL OPENING
FLARE MOLDING - INSTALLATION)
(7) Install the grille. (Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION)
REAR FASCIA
REMOVAL
(1) Remove the wheel flares (rear). (Refer to 23 -
BODY/EXTERIOR/REAR WHEEL OPENING
FLARE MOLDINGS - REMOVAL)
(2) Remove the rear lamp units. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
REAR LAMP UNIT - REMOVAL)(3) Remove the four side bolts. (Fig. 3)
(4) Remove the four bottom rivets.
(5) Remove the 3 bolts along the upper edge.
(6) Separate the side plastic retainers and remove
the fascia from the vehicle.
INSTALLATION
NOTE: Fascia must be pushed completely forward
to allow the plastic retainers full engagement in
their respective slots.
(1) Install the fascia and insert the plastic retain-
ers.
(2) Install the three upper bolts.
(3) Install the four side bolts.
(4) Install four bottom rivets.
(5) Install the rear lamp units. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/REAR
LAMP UNIT - INSTALLATION)
(6) Install the rear half wheel opening flares.
(Refer to 23 - BODY/EXTERIOR/WHEEL OPENING
FLARE MOLDING - INSTALLATION)
Fig. 2 FASCIA INNER SUPPORT
1 - INNER SUPPORT CLIP
2 - SIDE REPEATER CONNECTOR (IF EQUIPPED)
3 - FASCIA ASSEMBLY
4 - FOG LAMP
Fig. 3 REAR FASCIA
1 - REAR FASCIA ASSEMBLY
2 - PLASTIC RETAINERS
3 - FASCIA SUPPORT BRACKET
4 - SIDE BOLTS
5 - RIVETS
6 - UPPER BOLTS
13 - 2 FRAMES & BUMPERSKJ
FRONT FASCIA (Continued)

REAR FASCIA SUPPORT
REMOVAL
(1) Remove the rear fascia assembly. (Refer to 13 -
FRAME & BUMPERS/BUMPERS/REAR FASCIA -
REMOVAL)
(2) Remove the six rivets and remove the fascia
support (Fig. 4).
INSTALLATION
(1) Install the fascia support onto the vehicle and
install six new rivets.
(2) Install the rear fascia assembly. (Refer to 13 -
FRAME & BUMPERS/BUMPERS/REAR FASCIA -
INSTALLATION)
FRAME
SPECIFICATIONS
SPECIFICATIONS - FRAME DIMENSIONS
Frame dimensions are listed in metric scale. All
dimensions are from center to center of Principal
Locating Point (PLP), or from center to center of PLP
and fastener location.
VEHICLE PREPARATION
Position the vehicle on a level work surface. Using
screw or bottle jacks, adjust the vehicle PLP heights
to the specified dimension above a level work surface.
Vertical dimensions can be taken from the work sur-
face to the locations indicated were applicable.
NOTE: All measurements are in MM.
DIMENSION ILLUSTRATIONS
DESCRIPTION FIGURE
TOP VIEW ( 5 )
SIDE VIEW ( 6 )Fig. 4 REAR FASCIA SUPPORT
1 - RIVETS
2 - SUPPORT
KJFRAMES & BUMPERS 13 - 3