Exhaust System; Diagnosis And Testing; Diagnosis And Testing - Exhaust System Restriction Check - Chrysler 300M Service Manual

LH
EXHAUST SYSTEM (Continued)

DIAGNOSIS AND TESTING

DIAGNOSIS AND TESTING - EXHAUST SYSTEM
CONDITION
EXCESSIVE EXHAUST NOISE
(UNDER HOOD)
EXCESSIVE EXHAUST NOISE
DIAGNOSIS AND TESTING - EXHAUST SYSTEM
RESTRICTION CHECK
Exhaust system restriction can be checked by mea-
suring back pressure using the DRB III
module pressure tester.
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) Disconnect and remove the upstream (before
catalytic converter) oxygen sensor. (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/O2 SENSOR -
REMOVAL)
POSSIBLE CAUSES
1. Exhaust manifold cracked or
broken.
2. Manifold to cylinder head leak.
3. EGR tube to manifold gasket
leakage.
4. EGR Valve to EGR tube gasket
leakage.
5. Exhaust to manifold leak.
6. Pipe and shell noise from front
exhaust pipe.
1. Leak at exhaust pipe joints.
2. Burned or rusted out muffler
assembly or exhaust pipe.
3. Burned or rusted out
resonator(s).
4. Restriction in exhaust system.
5. Converter material in muffler or
resonators.
(2) Install the Exhaust Back Pressure Fitting
Adaptor CH8519.
(3) Connect the Low Pressure Sensor (15 psi)
CH7063 to the back pressure fitting.
and PEP
(4) Following the PEP module instruction manual,
connect all required cables to the DRB III and PEP
module. Select the available menu options on the
DRBIII display screen for using the digital pressure
gauge function.
(5) Apply the park brake and start the engine.
(6) With transmission in Park or Neutral, raise
engine speed to 2000 RPM. Monitor the pressure
readings on the DRBIII . Back pressure should not
exceed specified limit. Refer to specification in table
below EXHAUST BACK PRESSURE LIMITS.
NOTE: For applications with dual catalytic convert-
ers, repeat test on opposite converter using the
previous steps.

EXHAUST SYSTEM 11 - 3

CORRECTION
1. Replace manifold.
2. Tighten manifold and/or replace
gasket.
3. Tighten fasteners or replace
gasket.
4. Tighten fasteners or replace
gasket.
5. Tighten or replace V-Band Clamp.
6. Characteristic of single wall pipe.
1. Tighten clamps at leaking joints.
2. Replace exhaust module, rear
resonator/tailpipe assembly or
exhaust pipe with catalytic converter
assembly.
3. Replace resonator assembly.
4. Remove restriction if possible, or
replace components as necessary.
5. Replace muffler, resonators and
converter assemblies. Check fuel
injection and ignition systems for
proper operation.