2003 FORD MUSTANG catalytic converter

noise—
normally
accompanied by
vibration Powertrain/Drivetrain Mount Neutralizing in this
section.
z Damaged or
misaligned exhaust
system. z
INSPECT the exhaust
system for loose or broken
clamps and brackets.
CARRY OUT Exhaust System Neutralizing in this
section.
z Whistling noise—
normally
accompanied
with poor idle
condition z
Air intake system. zCHECK the air intake
ducts, air cleaner, throttle
body and vacuum hoses for
leaks and correct fit.
REPAIR or ADJUST as
necessary. REFER to
Section 303 - 12
z
Clunking noise zWater pump has
excessive end play or
imbalance. z
CHECK the water pump for
excessive end play.
INSPECT the water pump
with the drive belt off for
imbalance. INSTALL a new
water pump as necessary.
REFER to Section 303 -
03A .
z Generator has
excessive end play. z
CHECK the generator for
excessive end play.
REPAIR or INSTALL a new
generator. REFER to
Section 414 - 02 .
z Pinging noise zExhaust system leak. zINSPECT the exhaust
system for leaks. REPAIR
as necessary.
z Gasoline octane too
low. z
VERIFY with customer the
type of gasoline used.
CORRECT as necessary.
z Knock sensor
operation. z
CHECK the knock sensor.
INSTALL a new knock
sensor as necessary.
REFER to Section 303 - 14 .
z Incorrect spark
timing. z
CHECK the spark timing.
REPAIR as necessary.
z High operating
temperature. z
INSPECT cooling system
for leaks. CHECK the
coolant level. REFILL as
necessary. CHECK the
coolant for the correct mix
ratio. DRAIN and REFILL
as needed. CHECK engine
operating temperature is
within specifications.
REPAIR as necessary.
z Foul- out spark plug. zCHECK the spark plugs.
REPAIR or INSTALL new
spark plugs as necessary.
z Catalytic converter. zAcceptable noise.
z Knocking noise—
light knocking
noise, also z
Excessive clearance
between the piston
and the cylinder wall. z
Engine cold and at high
idle. Using an EngineEAR,
pull a spark plug or fuel Klj . 24 ba
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z
Excessive runout of
valve seats on the
valve face. z
CARRY OUT a valve seat
runout test. INSPECT the
valve face and seat.
INSTALL new valves as
necessary. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Rattling noise—
from the bottom
of the vehicle z
Loose muffler shields
or catalytic converter
shields. z
CHECK the exhaust
system for loose exhaust
shields. REPAIR as
necessary.
z Thumping
noise— from the
bottom of the
vehicle, worse at
acceleration z
Exhaust pipe/muffler
grounded to chassis. z
CHECK the exhaust
system to chassis
clearance. CHECK the
exhaust system hangers for
damage. REPAIR as
necessary. REFER to
Section 309 - 00 .
z Whoosh— occurs
during light
vehicle
acceleration.
Heard inside the
vehicle z
Throttling late,
creating turbulence
transmitted through
the plastic manifold. z
CHECK for leaks or
missing seal in the dash
panel.
z Engine
vibration—
increases
intensity as
engine rpm is
increased z
Engine out-of-
balance. z
CARRY OUT Neutral
Engine Run- Up (NERU)
Test. ROTATE the torque
converter, 120° for 3 bolt
and 180° for 4 bolt.
INSPECT the torque
converter pilot outer
diameter to crankshaft pilot
inner diameter. REPAIR as
necessary. REFER to
Section 307 - 01 .
z Engine
vibration— is felt
with increases
and decreases in
engine rpm z
Strain on exhaust
mounts. z
CARRY OUT the Exhaust
System Neutralizing
procedure in this section.
REPAIR as necessary.
z Damaged or worn
powertrain/drivetrain
mounts. z
CHECK the
powertrain/drivetrain
mounts for damage.
REPAIR as necessary.
z Engine or
transmission
grounded to chassis. z
INSPECT the
powertrain/drivetrain for
correct clearances.
REPAIR as necessary.
z Engine
vibration—
vibration felt at all
times z
Excessive engine
pulley runout. z
CARRY OUT Engine
Accessory Test. INSTALL a
new engine pulley as
necessary. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Damaged or worn
accessory
component. z
CARRY OUT Engine
Accessory Test. REPAIR or
INSTALL a new component Klj . 27 ba
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GENERAL PROCEDURES
Exhaust System Neutralizing
WARNING: Exhaust gases contain carbon monoxide, which is harmful to health and
potentially lethal. Repair exhaust system leaks immediately. Never operate the engine in an
enclosed area.
WARNING: Exhaust system components are hot.
NOTE: Neutralize the exhaust system to relieve strain on mounts which can be sufficiently bound up to
transmit vibration as if grounded.
1. WARNING: The electrical power to the air suspension system must be shut off prior
to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by
turning off the air suspension switch. Failure to do so can result in unexpected inflation
or deflation of the air springs, which can result in shifting of the vehicle during these
operations.
CAUTION: Make sure the system is warmed up to normal operating temperature, as
thermal expansion can be the cause of a strain problem.
Raise and support the vehicle.
2. Loosen all exhaust hanger attachments and reposition the hangers until they hang free and straight.
3. Loosen all exhaust flange joints.
4. Place a stand to support the muffler parallel to the vehicle frame with the muffler pipe bracket free of stress.
5. Tighten the muffler connection.
6. Tighten all the exhaust hanger clamps and flanges (tighten the exhaust manifold flange joint last).
zVerify there is adequate clearance to prevent grounding at any point in the system. Make
sure that the catalytic converter and heat shield do not contact the frame rails.
z After neutralization, the rubber in the exhaust hangers should show some flexibility when
movement is applied to the exhaust system.
z With the exhaust system installed securely and cooled, the rear hanger should be angled
forward.
7. Lower the vehicle.
8. Test the exhaust system for normal operation.
SECTION 100-
04: Noise, Vibration and Harshness 2003 Mustang Workshop Manual Klj . 1 ba
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The camshaft position sensor:
zsends the powertrain control module a signal indicating camshaft position, used for fuel
synchronization.
The crankshaft position sensor:
zsends the powertrain control module a signal indicating crankshaft position.
z is essential for calculating spark timing.
The mass air flow sensor:
zsends the powertrain control module a signal indicating mass air flow rate of air entering the
engine.
The intake air temperature sensor:
zsends the powertrain control module a signal indicating the temperature of the air entering the
engine.
The heated oxygen sensor:
zhas the ability to create a voltage signal depending on exhaust oxygen content.
z provides feedback information to the powertrain control module used to calculate fuel delivery.
The rear catalyst monitor sensor:
zmonitors oxygen content after the oxygen flows through the catalytic converter.
z provides a voltage to the powertrain control module used to calculate catalytic converter
integrity.
The wheel speed sensor:
zsends a signal to the powertrain control module indicating wheel speed. Klj . 2 ba
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DESCRIPTION AND OPERATION
Exhaust System
WARNING: The normal operating temperature of the exhaust system is very high. Never
attempt to repair any part of the system until it has cooled. Be especially careful when working
around the three way catalytic converter. The temperature of the three way catalytic converter
rises to a high level after only a few minutes of engine operation.
CAUTION: When repairing exhaust system or removing exhaust components, disconnect
all heated oxygen sensors (HO2S) at the wiring connectors to prevent damage to the heated
oxygen sensors and wiring harness. For additional information, refer to Section 303 - 14 for
location of the heated oxygen sensors.
The exhaust system:
zcontains dual three- way catalytic converters.
z has a crossover pipe downstream of the three way catalytic converters (4.6L).
z has two upstream heated oxygen sensors mounted before the three- way catalytic converters.
z the production muffler and tailpipe assembly is a one- piece design exhaust system.
Exhaust System — 3.8L Exhaust System — 4.6L (2V) SECTION 309-
00: Exhaust System 2003 Mustang Workshop Manual Item Part Number Description
1 5F250 Dual converter assembly
2 5D255 Insulator bracket assembly
3 5A246 Insulator bracket, (tailpipe)
4 5D255 Insulator bracket assembly
5 5232 Muffler Klj . 1 ba
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DIAGNOSIS AND TESTING
Exhaust System
Symptom Chart
SECTION 309-
00: Exhaust System 2003 Mustang Workshop Manual Symptom Chart
Condition
Possible Sources Action
z Noisy or
leaking
exhaust z
Broken or loose
clamps, hangers or
isolators.
z Punctures in the muffler
(5230).
z Broken, loose or
missing exhaust
manifold fasteners or
gaskets.
z Loose heated oxygen
or catalyst monitor
sensor. z
REPAIR as necessary.
z Exhaust system
misalignment. z
ALIGN exhaust system.
z Broken or loose
catalyst internal
components. z
LOOSEN all fasteners joining
the exhaust system and SHAKE
the system to isolate the
concern. REPAIR as necessary.
z Loss of
power z
Kinked or damaged
exhaust pipe.
z Clogged three- way
catalytic converter
(5F250).
z Foreign object in the
exhaust system. z
REPAIR as necessary. Klj . 1 ba
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REMOVAL AND INSTALLATION
Dual Converter Y-
Pipe —3.8L
Removal
NOTE: The RH and LH catalytic converters are serviceable separately.
1. Raise and support the vehicle. For additional information, refer to Section 100 - 02 .
2. CAUTION: When repairing the exhaust system or removing exhaust components,
disconnect all heated oxygen sensors (HO2S) (9F472) and catalyst monitor sensors at
the wiring connectors to prevent damage to the sensors and wiring harnesses.
Disconnect the RH and LH HO2S connectors.
3. Disconnect the RH and LH catalyst monitor sensor connectors.
4. Remove the dual converter assembly nuts.
SECTION 309-
00: Exhaust System 2003 Mustang Workshop Manual Klj . 1 ba
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REMOVAL AND INSTALLATION
Dual Converter H-
Pipe —4.6L (2V and 4V)
Removal
NOTE: The RH and LH catalytic converters are serviced separately.
1. Raise and support the vehicle. For additional information, refer to Section 100 - 02 .
2. CAUTION: When repairing exhaust system or removing the exhaust components,
disconnect all heated oxygen sensors (HO2S) (9F472) at the wiring connectors to prevent
damage to the heated oxygen sensors and wiring harness.
Disconnect the downstream RH and LH heated oxygen sensor connectors (9F472).
3. Disconnect the two upstream RH and LH catalyst monitor sensor connectors.
4. Remove the dual converter assembly nuts. (RH shown, LH similar.)
SECTION 309-
00: Exhaust System 2003 Mustang Workshop Manual Klj . 1 ba
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