Page 235 of 796

04-4
2. INSPECTION
1) Troubleshooting
When Abnormal Noises are Heard from the Engine Room ▶
For the vehicle equipped with DI engine, if a learning noise occurs in each range or other noises
occur, the major cause of it is a faulty turbocharger assembly. But an interference issue, poor
tightness or loose in the intake and exhaust system also can cause those noises. This is mainly
because the operator didn't follow the instruction exactly when reconnecting the intake hoses and
pipes which were disconnected to check the system or replace the air cleaner. If the intake system
is free of any faults, check the EGR and PCV oil separator connected to the intake system.
The figure may be different from the actual engine. Therefore, read thoroughly below before
replacing the parts.
2) Abnormal Noise Caused by Poor Tightness of Intake System
When the DI engine is running, the air entered into the engine flows in the sequence as shown above.
If high intake pressure is applied to the loose or damaged part, a whistling noise may occur, the intake
air volume is measured incorrectly or the engine power is derated.
Page 237 of 796
04-6
1. OVERVIEW
The intake system for D20DTR engine is equipped with a throttle body which includes a flap. This flap
is controlled by an electrical signal to cut off the intake air entering to the engine when the ignition
switch is turned off. Because of this, the shape of the intake manifold has been changed and improved
HFM sensor is newly adopted to control the intake air volume more precisely.
2. COMPONENT
2330-01 Intercooler assembly
2313-15 HFM sensor
HFM sensor, version 7
*For more information, refer to Chapter "Engine
Control".
2313-01 Air cleaner assembly
Page 243 of 796
05-31729-01
Muffler Assembly
1. MAJOR CHANGES
Muffler assembly parts (A, B) changed due to change of rear subframe
(A) Connecting pipe between muffler and tail silencer: moved by 20 mm
(B) Gap between tail silencer pipe and body: changed from 16 mm to 25 mm -
Page 246 of 796
05-6
2. LAYOUT
Silencer Assembly
Exhaust manifold assembly
CDPF assembly
1. OVERVIEW
This system purifies the exhaust gas generated by the combustion in the engine to reduce the
pollutants and noise during that arise during combustion.
Exhaust front pipe assembly
For more information, refer to Chapter
"Engine Control". *
Page 325 of 796
14-132412-02
Collecting PM
→ Regeneration
The engine ECU detects the
amount of PM collected by the
information from the
temperature sensors and
differential pressure sensor.
When the soot is accumulated,
the engine ECU performs post-
injection to increase the
exhaust gas temperature and
burns the collected PM at
approx. 600°C.Oxidation (DOC)
When the exhaust gas enters
into the CDPF assembly, its
CO, HC and PM are reduced
by the redox reaction of the
DOC. The remaining PM is
filtered and collected in CDPF,
and the temperature of the
exhaust gas is increased to
between 450 and 500°C.
5. OPERATING PROCESS
[Configuration and principle of operation]
The exhaust gas
passed through the
exhaust manifold
enters into the CDPF
assembly (at approx
250℃).
Page 382 of 796

01-70000-00
2. DESCRIPTION AND OPERATION
1) Cleanliness and Care
An automobile engine is a combination of many machined, honed, polished and lapped surfaces with
tolerances that are measured in the ten-thousandths of an inch. When any internal engine parts are
serviced, care and cleanliness are important. A liberal coating of engine oil should be applied to friction
areas during assembly, to protect and lubricate the surfaces on initial operation.
Proper cleaning and protection of machined surfaces and friction areas is part of the repair procedure.
This is considered standard shop practice even if not specifically stated.
Whenever valve train components are removed for service, they should be kept in order.
They should be installed in the same locations, and with the same mating surfaces, as when they were
removed. Battery cables should be disconnected before any major work is performed on the engine.
Failure to disconnect cables may result in damage to wire harness or other electrical parts.
2) On-Engine Service
Disconnect the negative battery cable before removing or installing any electrical unit, or when a
tool or equipment could easily come in contact with exposed electrical terminals.
Disconnecting this cable will help prevent personal injury and damage to the vehicle.
The ignition must also be in LOCK unless otherwise noted.
Notice Any time the air cleaner is removed, the intake opening -
Any time the air cleaner is removed, the intake opening should be covered. This will protect
against accidental entrance of foreign material, which could follow the intake passage into the
cylinder and cause extensive damage when the engine is started. -
Page 391 of 796

05-32420-01
1. OVERVIEW OF EXHAUST SYSTEM
When you are inspecting or replacing exhaust system components, make sure there is adequate
clearance from all points on the underbody to avoid possible overheating of the floor panel and
possible damage to the passenger compartment insulation and trim materials.
Check the complete exhaust system and the nearby body areas and trunk lid for broken,
damaged, missing or mispositioned parts, open seams, holes, loose connections, or othe
r
deterioration which could permit exhaust fumes to seep into the trunk may be an indication of a
problem in one of these areas. Any defects should be corrected immediately. -
2. OVERVIEW OF MUFFLER
Aside from the exhaust manifold connection, the exhaust system uses a flange and seal joint design
rather than a slip joint coupling design with clamp and U-bolts.
If hole, open seams, or any deterioration is discovered upon inspection of the front muffler and pipe
assembly, the complete assembly should be replace, the complete assembly should be replaced.
The same procedure is applicable to the rear muffler assembly. Heat shields for the front and rea
r
muffler assembly and catalytic converter protect the vehicle and the environment from the high
temperatures that the exhaust system develops.
3. OVERVIEW OF CATALYTIC CONVERTER
When jacking or lifting the vehicle from the body side rails, be certain that the lift pads do not
contact the catalytic converter, as this could damage the catalytic converter. -
Use of anything other than unleaded fuel will damage the catalyst in the catalytic converter. -
The catalytic converter are emission-control devices added to the exhaust system to reduce
pollutants from the exhaust pipes.
The oxidation catalyst is coated with a catalytic material containing platinum and palladium,
which reduces levels of hydrocarbon (HC) and carbon monoxide (CO) from the exhaust gas.
The three-way catalyst has coatings which contain platinum and rhodium, which additionall
y
lower the levels of oxides of nitrogen (NOx). -
-
Page 404 of 796

08-6
3. IGNITION SYSTEM OPERATION
This ignition system does not use a conventional distributor and coil. It uses a crankshaft position
sensor input to the Engine Control Module (ECM).
The ECM then determines Electronic Spark Timing (EST) and triggers the electronic ignition system
ignition coil.
This type of distributor less ignition system uses a "waste spark" method of spark distribution. Each
cylinder is paired with the cylinder that is opposite it (2.3L DOHC: 2 - 3 or 1 - 4, 3.2L DOHC: 1 - 6 or 2 -
5 or 3 - 4).
The spark occurs simultaneously in the cylinder coming up on the compression stroke and in the
cylinder coming up on the exhaust stroke.
The cylinder on the exhaust stroke requires very little of the available energy to fire the spark plug.
The remaining energy is available to the spark plug in the cylinder on the compression stroke. These
systems use the EST signal from the ECM to control the EST.
The ECM uses the following information: Engine load (mass air flow sensor, manifold air pressure
sensor).
Engine coolant temperature.
Intake air temperature.
Crankshaft position.
Engine speed (rpm).
1) Electronic Ignition System Ignition Coil
The Electronic Ignition (EI) system ignition coil is located on the cylinder head cover.
The double ended coils receive the signal for the ECM which controls the spark advance. Each
EI system ignition coil provides the high voltage to two spark plugs simultaneously;
3.2L DOHC
T1/1: cylinder 2 and 5
T1/2: cylinder 3 and 4
T1/3: cylinder 1 and 6
The EI system ignition coil is not serviceable and must be replaced as an assembly.