Chrysler Sebring, Stratus sedan, Sebring Convertible. Manual - part 535

INSPECTION

Inspect the exhaust pipes, catalytic converters,

muffler, and resonators for cracked joints, broken
welds and corrosion damage that would result in a
leaking exhaust system. Inspect the clamps, support
brackets, and insulators for cracks and corrosion
damage.

NOTE: Slip joint band clamps are spot welded to
exhaust system. If a band clamp must be replaced,
the spot weld must be ground off.

INSTALLATION - EXHAUST SYSTEM

NOTE: Always work from the front to rear of
exhaust

system

when

aligning

and

tightening

exhaust system components.

(1) Loosely install fasteners that attach exhaust

system to exhaust manifold (2.0L/2.4L)/cross-under
pipe (2.7L).

(2) Install support isolators to muffler supports.
(3) Align exhaust system to maintain position and

proper clearance with underbody parts. All support
isolators should have equal load on them. Tighten
fasteners that attach exhaust system to exhaust
manifold (2.0L/2.4L)/cross-under pipe (2.7L) to 28
N·m (250 in. lbs.).

(4) Vehicles

equipped

with

2.0L/2.4L

engines,

reconnect the downstream oxygen sensor connector.

(5) Connect ground strap to muffler.
(6) Lower vehicle.
(7) Start the engine and inspect for exhaust leaks.

Repair exhaust leaks as necessary.

(8) Check the exhaust system for contact with the

body panels. Make the necessary ajustments, if
needed.

ADJUSTMENTS

A misaligned exhaust system is usually indicated

by a vibration, rattling noise, or binding of exhaust
system components. These noises are sometimes hard
to distinguish from other chassis noises. Inspect
exhaust system for broken or loose clamps, heat
shields, isolators, and brackets. Replace or tighten as
necessary. It is important that exhaust system clear-
ances and alignment be maintained.

Perform the following procedures to align the

exhaust system:

(1) Loosen clamps and support brackets.
(2) Align the exhaust system starting at the front,

working rearward.

(3) Tighten all clamps and brackets once align-

ment and clearances are achieved.

SPECIFICATIONS

TORQUE

DESCRIPTION

N·m

Ft.

Lbs.

In.

Lbs.

Band Clamps—Fastener

—

Body Heat Shield—Fasteners

—

Catalytic Converter to Exhaust
Manifold Flange—Fasteners

—

250

Cross-Under Pipe —Fasteners (2.7L)

—

250

SPECIAL TOOLS

EXHAUST SYSTEM

DRB III & PEP Module - OT-CH6010A

Back Pressure Test Adapter - CH8519

Pressure Transducer CH7063

EXHAUST SYSTEM

11 - 5

EXHAUST SYSTEM (Continued)

CATALYTIC CONVERTER -
2.0L/2.4L

DESCRIPTION

The under-floor, three-way catalytic converter inlet

is connected to the exhaust manifold by use of a flex
joint and gasket. The outlet connects to the exhaust
system.

CAUTION: When servicing, care must be exercised
not to dent or bend the bellows or bellows cover of
the flex-joint. Should this occur, the flex-joint will
eventually fail and require the catalytic converter be
replaced.

An exhaust flex-joint coupling (Fig. 4) is used to

secure the catalytic converter to the engine manifold.

The exhaust flex-joint is welded to the catalytic

converter.

OPERATION

The three-way catalytic converter simultaneously

converts three exhaust emissions into harmless
gases. Specifically, HC and CO emissions are con-
verted into water (H2O) and carbon dioxide (CO2).
Oxides of Nitrogen (NOx) are converted into elemen-
tal Nitrogen (N) and water. The three-way catalyst is
most efficient in converting HC, CO and NOx at the
stoichiometric air fuel ratio of 14.7:1.

The oxygen content in a catalyst is important for

efficient conversion of exhaust gases. When a high
oxygen content (lean) air/fuel ratio is present for an
extended period, oxygen content in a catalyst can
reach a maximum. When a rich air/fuel ratio is
present for an extended period, the oxygen content in
the catalyst can become totally depleted. When this
occurs, the catalyst fails to convert the gases. This is
known as catalyst

9punch through.9

Catalyst operation is dependent on its ability to

store and release the oxygen needed to complete the
emissions-reducing chemical reactions. As a catalyst
deteriorates, its ability to store oxygen is reduced.
Since the catalyst’s ability to store oxygen is some-
what related to proper operation, oxygen storage can
be used as an indicator of catalyst performance.
Refer to the appropriate Diagnostic Information for
diagnosis of a catalyst related Diagnostic Trouble
Code (DTC).

The combustion reaction caused by the catalyst

releases additional heat in the exhaust system, caus-
ing temperature increases in the area of the reactor
under severe operating conditions. Such conditions
can exist when the engine misfires or otherwise does
not operate at peak efficiency. Do not remove spark
plug wires from plugs or by any other means short
out cylinders, if exhaust system is equipped with a
catalytic converter. Failure of the catalytic converter
can occur due to temperature increases caused by
unburned fuel passing through the converter. This
deterioration of the catalyst core can result in exces-
sively high emission levels, noise complaints, and
exhaust restrictions.

Unleaded gasoline must be used to avoid ruining

the catalyst core. Do not allow engine to operate
above 1200 RPM in neutral for extended periods over
5 minutes. This condition may result in excessive
exhaust system/floor pan temperatures because of no
air movement under the vehicle.

The flex joint allows flexing as the engine moves,

preventing breakage that could occur from the back-
and-forth motion of a transverse mounted engine.

CAUTION: Due to exterior physical similarities of
some catalytic converters with pipe assemblies,
extreme care should be taken with replacement
parts.

There

are

internal

converter

differences

required in some parts of the country (particularly
vehicles

built

for

States

with

strict

emission

requirements) and between model years.

REMOVAL

NOTE: In the following procedure it is not neces-
sary to separate the muffler/pipe assembly from the
resonator/pipe

assembly.

They

can

both

removed as an assembly.

Fig. 4 FLEX-JOINT COUPLING - TYPICAL

1 - BELLOWS
2 - COVER
3 - FLANGE

11 - 6

EXHAUST SYSTEM

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 vehicle on hoist and apply penetrating oil

to resonator/pipe assembly band clamp, and the fas-
teners that connect the catalytic converter to the
exhaust manifold.

(2) Remove ground strap from muffler.
(3) Loosen band clamp for resonator/pipe assembly.

CAUTION: Do not use any tools to remove the rub-
ber isolators–remove by hand only. Soapy water or
silicone–based lubricant spray may be used to
assist removal/installation of isolators. DO NOT use
a petroleum–based lubricant on the isolators, as
damage to the rubber material can occur.

(4) Remove support isolators from muffler sup-

ports.

(5) Remove resonator/pipe and muffler/pipe as an

assembly.

(6) Disconnect downstream oxygen sensor connec-

tor.

(7) Remove fasteners that attach catalytic con-

verter to the exhaust manifold. Remove catalytic con-
verter from vehicle.

(8) Remove and discard gasket.

INSPECTION

WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER ATTEMPT TO SERVICE ANY
PART OF THE EXHAUST SYSTEM UNTIL IT IS
COOLED. SPECIAL CARE SHOULD BE TAKEN
WHEN WORKING NEAR THE CATALYTIC CON-
VERTER. THE TEMPERATURE OF THE CONVERTER
RISES TO A HIGH LEVEL AFTER A SHORT PERIOD
OF ENGINE OPERATION TIME.

Check catalytic converter for a flow restriction.

(Refer to 11 - EXHAUST SYSTEM - DIAGNOSIS

AND TESTING) Exhaust System Restriction Check
for procedure.

Visually inspect the catalytic converter element by

using a borescope or equivalent. Remove oxygen sen-
sor(s) and insert borescope. If borescope is not avail-
able, remove converter and inspect element using a
flashlight. Inspect element for cracked or melted sub-
strate.

NOTE: Before replacing a catalytic converter, deter-
mine the root cause of failure. Most catalytic con-
verter failures are caused by air, fuel or ignition
problems. (Refer to Appropriate Diagnostic Informa-
tion) for test procedures.

INSTALLATION

NOTE: Always work from the front to rear of
exhaust

system

when

aligning

and

tightening

exhaust system components.

(1) Clean manifold to converter sealing surfaces.
(2) Position new gasket on exhaust manifold.

NOTE: If catalytic converter is being replaced,
transfer downstream oxygen sensor to new con-
verter.

(3) Loosely attach catalytic converter to exhaust

manifold.

(4) Loosely install resonator/pipe and muffler/pipe

assembly to catalytic converter outlet pipe.

(5) Install support isolators to muffler supports.
(6) Align exhaust system to maintain position and

proper clearance with underbody parts. All support
isolators should have equal load on them. Tighten
fasteners attaching catalytic converter to exhaust
manifold to 28 N·m (250 in. lbs.).

(7) Tighten resonator/pipe assembly band clamp to

54 N·m (40 ft. lbs.).

(8) Connect ground strap to muffler.
(9) Lower vehicle.
(10) Start the engine and inspect for exhaust

leaks. Repair exhaust leaks as necessary.

(11) Check the exhaust system for contact with the

body panels. Make the necessary ajustments, if
needed.

EXHAUST SYSTEM

11 - 7

CATALYTIC CONVERTER - 2.0L/2.4L (Continued)

CATALYTIC CONVERTER -
FRONT - 2.7L

REMOVAL

(1) Disconnect negative battery cable.
(2) Disconnect upstream oxygen sensor connector.
(3) Remove 3 converter attaching nuts that are

visible from the engine compartment (Fig. 5).

(4) Raise vehicle on hoist.
(5) Remove exhaust cross-under pipe (Refer to 11 -

EXHAUST

SYSTEM/CROSS-UNDER

PIPE

REMOVAL).

(6) Remove remaining bolt attaching converter to

exhaust manifold.

(7) Remove catalytic converter.
(8) Remove and discard gasket.

INSPECTION

Fig. 5 CATALYTIC CONVERTER - FRONT 2.7L

1 - STUD
2 - CATALYTIC CONVERTER
3 - GASKET

4 - HEAT SHIELD
5 - NUT

11 - 8

EXHAUST SYSTEM

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