1998 DODGE RAM 1500 catalytic converter

PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if the cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Carefully remove the radiator pressure cap from
the filler neck and check the coolant level. Push
down on the cap to disengage it from the stop tabs.
Wipe the inside of the filler neck and examine the
lower inside sealing seat for nicks, cracks, paint, dirt
and solder residue. Inspect the radiator-to- reserve/
overflow tank hose for internal obstructions. Insert a
wire through the hose to be sure it is not obstructed.
Inspect the cams on the outside of the filler neck.
If the cams are damaged, seating of the pressure cap
valve and tester seal will be affected.
Attach pressure tester (7700 or an equivalent) to
radiator filler neck.
Operate the tester pump to apply 103.4 kPa (15
psi) pressure to the system. If the hoses enlarge
excessively or bulges while testing, replace as neces-
sary. Observe the gauge pointer and determine the
condition of the cooling system according to following
criteria:
Holds Steady:If the pointer remains steady for
two minutes, serious coolant leaks are not present in
system. However, there could be an internal leakthat does not appear with normal system test pres-
sure. If it is certain that coolant is being lost and
leaks cannot be detected, inspect for interior leakage
or perform Internal Leakage Test. Refer to INTER-
NAL LEAKAGE INSPECTION.
Drops Slowly:Indicates a small leak or seepage
is occurring. Examine all of the connections for seep-
age or slight leakage with a flashlight. Inspect the
radiator, hoses, gasket edges and heater. Seal the
small leak holes with a Sealer Lubricant (or equiva-
lent). Repair the leak holes and inspect the system
again with pressure applied.
Drops Quickly:Indicates that serious leakage is
occurring. Examine the system for external leakage.
If leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove the engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove the engine dipstick and inspect for water
globules. Also inspect the transmission dipstick for
water globules and transmission fluid cooler for leak-
age.
WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 145 kPa (21 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate the engine without the pressure cap on
the radiator until the thermostat opens. Attach a
Pressure Tester to the filler neck. If pressure builds
up quickly it indicates a combustion leak exists. This
is usually the result of a cylinder head gasket leak or
crack in engine. Repair as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of the gauge pointer indicates compres-
sion or combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter,do notshort out cylinders to isolate com-
pression leak.
If the needle on dial of the pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
Fig. 5 Leak Detection Using Black Light - Typical
1 - TYPICAL BLACK LIGHT TOOL
7 - 6 COOLINGDR
COOLING (Continued)

EXHAUST SYSTEM
TABLE OF CONTENTS
page page
EXHAUST SYSTEM
DESCRIPTION
DESCRIPTION........................1
DESCRIPTION - 5.9L DIESEL.............3
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - GAS ENGINE . . . 4
DIAGNOSIS AND TESTING - DIESEL
ENGINE..............................5
SPECIFICATIONS - TORQUE...............5
SPECIAL TOOLS........................6
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER.....6
OPERATION............................6
REMOVAL
REMOVAL............................6
REMOVAL............................6
INSPECTION...........................6
INSTALLATION
INSTALLATION........................6
INSTALLATION........................7
EXHAUST PIPE
REMOVAL - 3.7L/4.7L/5.7L.................7
INSPECTION...........................7
INSTALLATION - 3.7L/4.7L/5.7L..............7
EXHAUST PIPE
REMOVAL - DIESEL......................7
INSPECTION...........................8
INSTALLATION - DIESEL..................8
HEAT SHIELDS
DESCRIPTION..........................8
REMOVAL.............................8
INSTALLATION..........................8
MUFFLER
REMOVAL.............................9INSTALLATION..........................9
MUFFLER - 5.9L DIESEL
REMOVAL.............................10
INSTALLATION.........................10
TAILPIPE - 5.9L DIESEL
REMOVAL.............................10
INSPECTION..........................10
INSTALLATION.........................11
TAILPIPE
REMOVAL.............................11
INSPECTION..........................11
INSTALLATION.........................11
TURBOCHARGER SYSTEM
DIAGNOSIS AND TESTING -
TURBOCHARGER BOOST PRESSURE.....11
TURBOCHARGER
DESCRIPTION.........................12
OPERATION...........................13
REMOVAL.............................14
CLEANING............................15
INSPECTION..........................15
INSTALLATION.........................15
CHARGE AIR COOLER AND PLUMBING
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS..............16
REMOVAL.............................17
CLEANING............................17
INSPECTION..........................17
INSTALLATION.........................17
EXHAUST SYSTEM
DESCRIPTION
DESCRIPTION
CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.The federal gasoline engine exhaust system con-
sists of engine exhaust manifolds, exhaust pipes, cat-
alytic converter(s), extension pipe (if needed),
exhaust heat shields, muffler and exhaust tailpipe
(Fig. 1), (Fig. 2), (Fig. 3)
The California emission vehicles exhaust system
also contains the above components as well as mini
catalytic converters added to the exhaust pipe.
The exhaust system must be properly aligned to
prevent stress, leakage and body contact. Minimum
clearance between any exhaust component and the
body or frame is 25.4 mm (1.0 in.). If the system con-
tacts any body panel, it may amplify objectionable
noises from the engine or body.
DREXHAUST SYSTEM 11 - 1

Fig. 1 Exhaust System - 3.7L Engine - Typical
1 - CATALYTIC CONVERTER
2 - TORCA CLAMP
3 - INSULATOR4 - MUFFLER
5 - TAILPIPE
Fig. 2 Exhaust System 4.7L Engine - Typical
1 - CATALYTIC CONVERTER
2 - TORCA CLAMP
3 - EXTENSION PIPE4 - INSULATOR
5 - MUFFLER
6 - TAILPIPE/RESONATOR
11 - 2 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

DESCRIPTION - 5.9L DIESEL
CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.
The diesel engine exhaust system consists of an
engine exhaust manifold, turbocharger, exhaust pipe,
resonator, extension pipe, muffler and exhaust
tailpipe.California emission vehicles include a catalytic con-
verter.
The exhaust system must be properly aligned to
prevent stress, leakage and body contact. The
exhaust components should be kept a minimum of
25.4 mm (1.0 in.) away from the body and frame. If
the system contacts any body panel, it may amplify
objectionable noises from the engine or body.
Fig. 3 Exhaust System 5.7L Engine - Typical
1 - CATALYTIC CONVERTER
2 - TORCA CLAMP
3 - EXTENSION PIPE4 - INSULATOR
5 - MUFFLER
6 - TAILPIPE/RESONATOR
DREXHAUST SYSTEM 11 - 3
EXHAUST SYSTEM (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - GAS ENGINE
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts 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.
11 - 4 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

SPECIAL TOOLS
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 the
cause 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.
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
REMOVAL
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 the nuts from the clamp that hold the
catalytic converter to the exhaust pipe flange connec-
tion.
NOTE: Do not remove nut from T-Bolt. Only remove
nut far enough, so that the T end can be removed
from the clamp.
(6) Remove the T bolt end of the fastener, from the
clamp.
(7) Spread the clamp, and remove the catalytic
converter from the vehicle.
(8) Discard the clamp.
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts.
(4) Remove 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
INSTALLATION
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
TURBOCHARGER TESTER 9022
11 - 6 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

(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 54.2 N´m (40 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(7) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Install the exhaust pipe onto exhaust mani-
folds, tighten 31 N´m (23 ft. lbs.).
(3) Tighten all clamp nuts to 52.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(6) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
EXHAUST PIPE
REMOVAL - 3.7L/4.7L/5.7L
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove exhaust pipe to manifold bolts, retain-
ers and nuts.
(4) Remove the clamp nuts.
(5) Remove the exhaust pipe (Fig. 4).
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION - 3.7L/4.7L/5.7L
(1) Position the exhaust pipe for proper clearance
with the frame and underbody parts. A minimum
clearance of 25.4 mm (1.0 in.) is required.
(2) Position the exhaust pipe to manifold. Install
the bolts, retainers and nuts. Tighten the nuts to 31
N´m (23 ft. lbs.) torque.
(3) Tighten the clamp nuts to 54.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
EXHAUST PIPE
REMOVAL - DIESEL
(1) Disconnect the battery negative cables.
(2) Raise and support the vehicle on a hoist.
(3) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(4) Remove the exhaust pipe-to-extension pipe
clamp. Separate the exhaust pipe and extension pipe.
(5) Remove the exhaust pipe-to-turbocharger elbow
clamp (Fig. 5).
(6) Remove the exhaust pipe from the transmis-
sion support (Fig. 5).
Fig. 4 Exhaust Pipe to Manifold Connection -
Typical
1 - BOLT
2 - RETAINER
3 - EXHAUST MANIFOLD
4 - NUT
5 - EXHAUST PIPE
DREXHAUST SYSTEM 11 - 7
CATALYTIC CONVERTER (Continued)

(4) Install MAP sensor mounting bolts (screws).
Refer to Torque Specifications.
(5) Connect electrical connector.
5.7L V-8
The Manifold Absolute Pressure (MAP) sensor is
mounted to the front of the intake manifold air ple-
num box (Fig. 24).
(1) Clean MAP sensor mounting hole at intake
manifold.
(2) Check MAP sensor o-ring seal for cuts or tears.
(3) Position sensor into manifold.
(4) Rotate sensor 1/4 turn clockwise for installa-
tion.
(5) Connect electrical connector.
OXYGEN SENSOR
DESCRIPTION
The Oxygen Sensors (O2S) are attached to, and
protrude into the vehicle exhaust system. Depending
on the engine or emission package, the vehicle may
use a total of either 2 or 4 sensors.
Federal Emission Packages :Two sensors are
used: upstream (referred to as 1/1) and downstream
(referred to as 1/2). With this emission package, the
upstream sensor (1/1) is located just before the main
catalytic convertor. The downstream sensor (1/2) is
located just after the main catalytic convertor.
California Emission Packages:On this emis-
sions package, 4 sensors are used: 2 upstream
(referred to as 1/1 and 2/1) and 2 downstream
(referred to as 1/2 and 2/2). With this emission pack-
age, the right upstream sensor (2/1) is located in the
right exhaust downpipe just before the mini-catalytic
convertor. The left upstream sensor (1/1) is located in
the left exhaust downpipe just before the mini-cata-
lytic convertor. The right downstream sensor (2/2) is
located in the right exhaust downpipe just after the
mini-catalytic convertor, and before the main cata-
lytic convertor. The left downstream sensor (1/2) is
located in the left exhaust downpipe just after the
mini-catalytic convertor, and before the main cata-
lytic convertor.
REMOVAL
CAUTION: Never apply any type of grease to the
oxygen sensor electrical connector, or attempt any
soldering of the sensor wiring harness.
Refer to (Fig. 26) or (Fig. 27) for typical O2S (oxy-
gen sensor) locations.WARNING: THE EXHAUST MANIFOLD, EXHAUST
PIPES AND CATALYTIC CONVERTER BECOME
VERY HOT DURING ENGINE OPERATION. ALLOW
ENGINE TO COOL BEFORE REMOVING OXYGEN
SENSOR.
(1) Raise and support vehicle.
(2) Disconnect wire connector from O2S sensor.
CAUTION: When disconnecting sensor electrical
connector, do not pull directly on wire going into
sensor.
(3) Remove O2S sensor with an oxygen sensor
removal and installation tool.
(4) Clean threads in exhaust pipe using appropri-
ate tap.
Fig. 26 O2 SENSOR SYSTEM - WITH 4 SENSORS
Fig. 27 O2 SENSOR SYSTEM - WITH 2 SENSORS
1 - POST CATALYST OXYGEN SENSOR (1/3)
2 - PRE-CATALYST OXYGEN SENSOR (1/2)
DRFUEL INJECTION - GAS 14 - 35
MAP SENSOR (Continued)