spark plugs replace CHRYSLER VOYAGER 2001 User Guide

ROCKER ARMS
REMOVAL
NOTE: This procedure is for in-vehicle service with
camshafts installed.
(1) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(2) Remove fuel rail. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL RAIL - REMOVAL)
(3) Remove spark plugs.
(4) Rotate engine until the camshaft lobe, on the
follower being removed, is position on its base circle
(heel). Also, the piston should be a minimum of 6.3
mm (0.25 in) below TDC position.
CAUTION: If cam follower assemblies are to be
reused, always mark position for reassembly in
their original positions.
(5) Using Special Tools 8215 and 8436 slowly
depress valve assembly until rocker arm can be
removed (Fig. 39).
NOTE: It may be necessary to remove additional
brackets or components to allow clearance for tool
handle movement.
(6) Repeat removal procedure for each rocker arm.
INSPECTION
Inspect the rocker arm for wear or damage (Fig.
40). Replace as necessary.
INSTALLATION
(1) Lubricate rocker arm with clean engine oil.
(2) Using Special Tools 8215 and 8436 slowly
depress valve assembly until rocker arm can be
installed on the hydraulic lifter and valve stem (Fig.
39).
(3) Repeat installation procedure for each rocker
arm.
(4) Install spark plugs.
(5) Install fuel rail. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL RAIL - INSTALLATION)
(6) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
ENGINE BLOCK
DESCRIPTION
The cast iron cylinder block is a two-piece assem-
bly, consisting of the cylinder block and bedplate (Fig.
41). The bedplate incorporates the main bearing caps
and bolts to the cylinder block. This design offers a
much stronger lower end and increased cylinder
block rigidity. The rear oil seal retainer is integral
with the block. The bedplate and block are serviced
as an assembly.
STANDARD PROCEDURE - PISTON TO
CYLINDER BORE FITTING
Piston and cylinder wall must be clean and dry.
Piston diameter should be measured 90 degrees to
piston pin about 14 mm (9/16 inch.) from the bottom
of the skirt as shown in (Fig. 43). Cylinder bores
Fig. 39 Rocker Arm - Removal/Installation
1 - SPECIAL TOOL 8215
2 - ROCKER ARM
3 - SPECIAL TOOL 8436
Fig. 40 Rocker Arm
1 - TIP
2 - LASH ADJUSTER POCKET
3 - ROLLER
RSENGINE 2.4L9-33

CONDITION POSSIBLE CAUSE CORRECTION
ENGINE STALLS
OR IDLES
ROUGH1. Idle speed too low. 1. Test minimum air flow. (Refer to
Appropriate Diagnostic Information)
2. Incorrect fuel mixture. 2. (Refer to Appropriate Diagnostic
Information)
3. Intake manifold leakage. 3. Inspect intake manifold, manifold gasket,
and vacuum hoses.
4. Faulty ignition coil(s). 4. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
ENGINE LOSS OF
POWER1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap.
2. Contamination in fuel system. 2. Clean system and replace fuel filter.
3. Faulty fuel pump. 3. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust system. 8. Perform exhaust restriction test. (Refer to
11 - EXHAUST SYSTEM - DIAGNOSIS AND
TESTING) Install new parts, as necessary.
9. Faulty ignition coil(s). 9. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
ENGINE MISSES
ON
ACCELERATION1. Dirty or incorrectly gapped spark plugs. 1. Clean spark plugs and set gap.
2. Contamination in Fuel System. 2. Clean fuel system and replace fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty ignition coil(s). 4. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
ENGINE MISSES
AT HIGH SPEED1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
2. Faulty ignition coil(s). 2. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
3. Dirty fuel injector(s). Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
4. Contamination in fuel system. 4. Clean system and replace fuel filter.
RSENGINE 3.3/3.8L9-75
ENGINE 3.3/3.8L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL PRESSURE
DROP1. Low oil level. 1. Check engine oil level.
2. Faulty oil pressure sending unit. 2. Install new sending unit.
3. Low oil pressure. 3. Check sending unit and main bearing oil
clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Oil pump relief valve stuck. 7. Remove valve and inspect, clean, or
replace.
8. Oil pump suction tube loose. 8. Remove oil pan and install new tube or
clean, if necessary.
9. Oil pump cover warped or cracked. 9. Install new oil pump.
10. Excessive bearing clearance. 10. Measure bearings for correct clearance.
OIL LEAKS 1. Misaligned or deteriorated gaskets. 1. Replace gasket(s).
2. Loose fastener, broken or porous metal
part.2. Tighten, repair or replace the part.
3. Misaligned or deteriorated cup or
threaded plug.3. Replace as necessary.
OIL
CONSUMPTION
OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as necessary.
(Refer to 25 - EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV VALVE -
DIAGNOSIS AND TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check grooves. If
groove is not proper width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or damaged. 6. Replace seal(s).
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
RSENGINE 3.3/3.8L9-77
ENGINE 3.3/3.8L (Continued)

²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak. If a leak is
present in this area, remove transmission for further
inspection.
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible thecrankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
(7) After the oil leak root cause and appropriate
corrective action have been identified, replace compo-
nent(s) as necessary.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Disconnect the ignition coil electrical connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor Special Tool
8116 or the equivalent, into the #1 spark plug hole in
cylinder head. Connect the 0±500 psi (Blue) pressure
transducer with cable adaptors to the DRBIIIt.
(7) Crank engine until maximum pressure is
reached on gage. Record this pressure as #1 cylinder
pressure.
(8) Repeat the previous step for all remaining cyl-
inders.
(9) Compression should not be less than 689 kPa
(100 psi) and not vary more than 25 percent from cyl-
inder to cylinder.
(10) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(11) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
9 - 78 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)

INSTALLATION
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Inspect seal on the cover bolt for wear or dam-
age (Fig. 24). Replace bolt assembly as necessary.
NOTE: The cylinder head cover bolts contain a
torque limiter sleeve and a seal (Fig. 24). The seal
and torque sleeve is replaced with the bolt.
(3) Assemble gasket to cylinder cover by inserting
the bolt assemblies through each bolt hole on the
cover and gasket (Fig. 24).
(4) Install cylinder head cover and bolts (Fig. 25).
(5) Tighten cylinder head cover bolts to 12 N´m
(105 in. lbs.) (Fig. 25).
(6) Connect PCV hose to cylinder head cover.
(7) Connect power steering pump supply hose sup-
port clip to cylinder head cover (Fig. 22).
(8) Connect spark plug wires to spark plugs.
(9) Install wiper module. (Refer to 8 - ELECTRI-
CAL/WIPERS/WASHERS/WIPER MODULE -
INSTALLATION)
(10) Connect negative cable to battery.
CYLINDER HEAD COVER -
LEFT
REMOVAL
(1) Disconnect spark plug wires from spark plugs.
(2) Disconnect crankcase vent hose from cylinder
head cover.
(3) Remove cylinder head cover bolts.
(4) Remove cylinder head cover and gasket.
Fig. 23 PCV Hose
1 - HOSE - PCV
2 - P C V VA LV E
Fig. 24 CYLINDER HEAD COVER GASKET
1 - CYLINDER HEAD COVER
2 - BOLT
3 - SEAL (SERVICED WITH BOLT)
4 - GASKET
Fig. 25 Cylinder Head Cover
1 - CYLINDER HEAD COVER
2 - BOLT
9 - 98 ENGINE 3.3/3.8LRS
CYLINDER HEAD COVER - RIGHT (Continued)

INSTALLATION
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Assemble gasket to cylinder cover by inserting
the fasteners through each bolt hole on cover and
gasket (Fig. 24).
(3) Install the cylinder head cover and bolts (Fig.
25).
(4) Tighten cylinder head cover bolts to 12 N´m
(105 in. lbs.) (Fig. 25).
(5) Connect crankcase vent hose.
(6) Connect spark plug wires to spark plugs.
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves have chrome plated valve stems with
four-bead lock grooves. The valve stem seals are
made of Viton rubber.
OPERATION
The two valves per cylinder are opened using
hydraulic lifters, push rods, and rocker arms.
STANDARD PROCEDURE - REFACING VALVES
AND VALVE SEATS
The intake and exhaust valves and seats are
machined to specific angles (Fig. 26).
VALVES
(1) Inspect the remaining margin after the valves
are refaced (Fig. 27). (Refer to 9 - ENGINE - SPEC-
IFICATIONS)
VALVE SEATS
CAUTION: Remove metal from valve seat only. Do
not remove material from cylinder head (Fig. 28).
(1) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.
Fig. 26 Valve Face and Seat
1 - SEAT WIDTH
2 - FACE ANGLE
3 - SEAT ANGLE
4 - SEAT CONTACT AREA
Fig. 27 Valve Margin
1 - VALVE FACE
2 - VALVE MARGIN
Fig. 28 Refacing Valve Seats
1 - REFACING STONE MUST NOT CUT INTO CYLINDER HEAD
2-STONE
3 - PILOT
4 - SEAT
RSENGINE 3.3/3.8L9-99
CYLINDER HEAD COVER - LEFT (Continued)

(8) Locate the forcing screw and spring retainer
adapter assembly over the spring requiring removal
(Fig. 36).
(9) Slowly turn the forcing screw clockwise (com-
pressing the valve spring) until the valve keepers can
be removed.
(10) Turn forcing screw counterclockwise to relieve
spring tension. Remove retainer and valve spring.
(11) Repeat procedure for each cylinder requiring
valve spring removal.
INSPECTION
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested (Fig. 37).As an example;the compression
length of a spring to be tested is 38.00 mm (1.496
in.). Turn the table of Tool C-647 until surface is in
line with the 38.00 mm (1.496 in.) mark on the
threaded stud and the zero mark on the front. Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by two. This will give
the spring load at test length. Fractional measure-
ments are indicated on the table for finer adjust-
ments. Refer to Engine Specifications to obtain
specified height and allowable tensions (Refer to 9 -
ENGINE - SPECIFICATIONS). Replace any springs
that do not meet specifications.
INSTALLATION - CYLINDER HEAD OFF
(1) If removed, install a new valve stem seal.
(Refer to 9 - ENGINE/CYLINDER HEAD/VALVE
STEM SEALS - INSTALLATION)
(2) Position valve spring and retainer on spring
seat.(3) Using Special Tool C-3422-C with 8464 Adapter
(Fig. 35), compress the spring only enough to install
the valve retainer locks.
(4) Slowly release the spring tension. Ensure the
retainer locks are seated properly.
INSTALLATION - CYLINDER HEAD ON
(1)The intake valve stem seals should be pushed
firmly and squarely over the valve guide using the
valve stem as guide.Do Not Force
seal against top of
guide. When installing the valve retainer locks, com-
press the springonly enoughto install the locks.
CAUTION: Do not pinch seal between retainer and
top of valve guide.
(2) Follow the same procedure on the remaining 5
cylinders using the firing sequence 1-2-3-4-5-6.Make
sure piston in cylinder is at TDC on the valve
spring that is being covered.
(3) Remove spark plug adapter tool.
(4) Install rocker arms and shaft assembly. (Refer
to 9 - ENGINE/CYLINDER HEAD/ROCKER ARMS -
INSTALLATION)
(5) Install cylinder head covers. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
(6) Install spark plugs and connect wires.
(7) Connect negative cable to battery.
ROCKER ARMS
DESCRIPTION - ROCKER ARMS
The rocker arms are installed on the rocker arm
shaft. The rocker arms and shaft assembly is attached
to the cylinder head with seven bolts and retainers.
The rocker arms are made of stamped steel.
Fig. 36 VALVE SPRING - REMOVE/INSTALL (HEAD ON)
1 - SPECIAL TOOL 8453
2 - BOLTS - SPECIAL TOOL ATTACHING
3 - AIR SUPPLY HOSE ADAPTER
Fig. 37 TESTING VALVE SPRING
1 - SPECIAL TOOL C-647
RSENGINE 3.3/3.8L9 - 103
VALVE SPRINGS (Continued)

INSPECTION
Inspect exhaust manifolds for damage or cracks
and check distortion of the cylinder head mounting
surface and exhaust crossover mounting surface with
a straightedge and thickness gauge (Fig. 148).
Manifold surface flatness limits should not exceed
1.0 mm (0.039 in.).
INSTALLATION
(1) Position exhaust manifold on cylinder head
(Fig. 147). Install bolts to center runner (cylinder #4)
and initial tighten to 2.8 N´m (25 in. lbs.).
(2) Using a new gasket, attach crossover pipe to
exhaust manifold and tighten bolts to 41 N´m (30 ft.
lbs.) (Fig. 146).
NOTE: Inspect crossover pipe fasteners for damage
from heat and corrosion. The cross-over bolts are
made of a special stainless steel alloy. If replace-
ment is required, OEM bolts are highly recom-
mended.
(3) Position heat shield on manifold (Fig. 147).
(4) Install the remaining manifold attaching bolts.
Tighten all bolts to 23 N´m (200 in. lbs.).
(5) Install and tighten heat shield attaching nut to
12 N´m (105 in. lbs.) (Fig. 147).
(6) Connect battery negative cable.
VALVE TIMING
VALVE TIMING VERIFICATION
(1) Remove front cylinder head cover and all 6
spark plugs.(2) Rotate engine until the #2 piston is at TDC of
the compression stroke.
(3) Install a degree wheel on the crankshaft pulley.
(4) With proper adaptor, install a dial indicator
into #2 spark plug hole. Using the indicator find TDC
on the compression stroke.
(5) Position the degree wheel to zero.
(6) Remove dial indicator from spark plug hole.
(7) Place a 5.08 mm (0.200 in.) spacer between the
valve stem tip of #2 intake valve and rocker arm pad.
Allow tappet to bleed down to give a solid tappet
effect.
(8) Install a dial indicator so plunger contacts the
#2 intake valve spring retainer as nearly perpendic-
ular as possible. Zero the indicator.
(9) Rotate the engine clockwise until the intake
valve has lifted .254 mm (0.010 in.).
CAUTION: Do not turn crankshaft any further clock-
wise as intake valve might bottom and result in
serious damage.
(10) Degree wheel should read 6 degrees BTDC to
6 degrees ATDC.
TIMING CHAIN COVER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(3) Raise vehicle on hoist.
(4) Drain engine oil.
(5) Remove right wheel and inner splash shield.
(6) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(7) Remove oil pick-up tube (Fig. 149).
(8) Remove accessory drive belt. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(9) Remove A/C compressor and set aside.
(10) Remove crankshaft vibration damper. (Refer
to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(11) Remove radiator lower hose.
(12) Remove heater hose from timing chain cover
housing (Fig. 150) or water pump inlet tube (if
engine oil cooler equipped) (Fig. 151).
(13) Remove the right side engine mount. (Refer to
9 - ENGINE/ENGINE MOUNTING/RIGHT MOUNT
- REMOVAL)
(14) Remove idler pulley from engine bracket (Fig.
152).
(15) Remove the engine mount bracket (Fig. 152).
(16) Remove cam sensor from timing chain cover
(Fig. 152).
Fig. 148 Check Exhaust Manifold Mounting
1 - STRAIGHT EDGE
2 - CROSSOVER PIPE MOUNTING SURFACE
3 - FEELER GAUGE
RSENGINE 3.3/3.8L9 - 153
EXHAUST MANIFOLD - LEFT (Continued)

CATALYTIC CONVERTER
DESCRIPTION
The toe board three-way catalytic converter is con-
nected to the exhaust manifold by the use of flex
joint and a gasket. The outlet connects to the muffler
inlet pipe and is secured with a band type clamp
(Fig. 1).
The exhaust flex-joint coupling (Fig. 3) is used to
secure the catalytic converter to the exhaust mani-
fold. The flex-joint has four bolts, four flag nuts and
a gasket that are separate parts from the exhaust
flex-joint. The flex-joint is welded to the catalytic
converter.
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.
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 canreach 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 catalyst9punch 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 Powertrain Diagnostic Pro-
cedure 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 notremove 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.
The use of catalysts also involves some non-auto-
motive problems. Unleaded gasoline must be used to
avoid poisoning 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
(1) Loosen clamp and disconnect the muffler/reso-
nator assembly from catalytic converter pipe.
(2) Disconnect downstream oxygen sensor electri-
cal connector (Fig. 4). For removal of downstream
oxygen sensor, (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/O2 SENSOR - REMOVAL).
Fig. 3 Flex-joint
1 - FLANGE
2 - END CAPS
3 - CATALYTIC CONVERTER
4 - FLEXIBLE BELLOWS
11 - 4 EXHAUST SYSTEMRS

TEST ACTION APPLICABILITY
8 The following items need to be checked as a possible cause for a no start condition.
Refer to any Technical Service Bulletins that may apply to the symptom.
The spark plugs must be free from fuel, oil, coolant and/or any foreign material or
deposits.
The fuel must be free from contamination.
The exhaust may be free from restrictions.
The engine compression must be within specifications.
The engine valve timing must be within specifications.
The engine must be free from vacuum leaks.
Were any of the above conditions found?All
Ye s®Repair as necessary.
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Test Complete.
9 Turn the ignition off.
Disconnect the fuel pump module harness connector.
Turn the ignition on.
With the DRBIIIt, actuate the ASD Fuel System test.
Using a 12 volt test light connected to ground, probe the Fuel Pump Relay Output
circuit at the Fuel Pump Module harness connector.
Does the test light illuminate brightly?All
Ye s®Go To 10
No®Go To 12
Caution: Stop All Actuations.
10 Turn the ignition off.
Disconnect the Fuel Pump Module harness connector.
Note: Check connectors - It is critical that the connector is free from any
signs of corrosion or deformities - Clean/repair as necessary.
Using a test light connected to battery voltage, probe the Fuel Pump ground circuit
at the Fuel Pump Module harness connector.
Does the test light illuminate brightly?All
Ye s®Go To 11
No®Repair the open/high resistance in the fuel pump ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER-1.
11 If there are no possible causes remaining, view repair. All
Repair
Replace the Fuel Pump Module.
Perform POWERTRAIN VERIFICATION TEST VER-1.
12 Turn the ignition off.
Remove the Fuel Pump Relay from the IPM.
With a 12 volt test light connected to ground, probe the Fuel Pump Relay Fused B+
circuit in the IPM.
Does the test light illuminate?All
Ye s®Go To 13
No®Check for an open Fuel Pump fuse, repair cause of open. If OK,
replace the IPM Fuse & Relay Center.
Perform POWERTRAIN VERIFICATION TEST VER-1.
256
STARTING
*ENGINE CRANKS DOES NOT START ÐContinued