17-1

ENGINE AND
EMISSION
CONTROL
CONTENTS

ENGINE CONTROL SYSTEM . . . . . . . . . 2 EVAPORATIVE EMISSION CONTROL

SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
GENERAL INFORMATION . . . . . . . . . . . . . . . . 2
General Information . . . . . . . . . . . . . . . . . . . . . . . 10
SERVICE SPECIFICATIONS . . . . . . . . . . . . . . . 2 System Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 10
ON-VEHICLE SERVICE . . . . . . . . . . . . . . . . . . . 2 Component Location . . . . . . . . . . . . . . . . . . . . . . 10
Accelerator Cable Check and Purge Control System Check . . . . . . . . . . . . . . . 11
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Purge Port Vacuum Check . . . . . . . . . . . . . . . . . 11
ACCELERATOR CABLE AND PEDAL . . . . . . 3 Purge Control Solenoid Valve Check . . . . . . . . . 12
EMISSION CONTROL SYSTEM . . . . . . 4 Check Valve Check . . . . . . . . . . . . . . . . . . . . . . . 12
GENERAL INFORMATION . . . . . . . . . . . . . . . . 4 EXHAUST GAS RECIRCULATION (EGR)
Emission Control Device Reference SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
General Information . . . . . . . . . . . . . . . . . . . . . . . 13
SERVICE SPECIFICATIONS . . . . . . . . . . . . . . 5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
VACUUM HOSE . . . . . . . . . . . . . . . . . . . . . . . . . . 5 System Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Vacuum Hose Piping Diagram . . . . . . . . . . . . . . 5 Component Location . . . . . . . . . . . . . . . . . . . . . . 14
Vacuum Circuit Diagram . . . . . . . . . . . . . . . . . . . . 6 Exhaust Gas Recirculation (EGR) Control System
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Vacuum Hose Check . . . . . . . . . . . . . . . . . . . . . . 7
EGR Valve Check . . . . . . . . . . . . . . . . . . . . . . . . . 15
Vacuum Hose Installation . . . . . . . . . . . . . . . . . . 7
EGR Port Vacuum Check . . . . . . . . . . . . . . . . . . 15
CRANKCASE EMISSION CONTROL EGR Control Solenoid Valve Check . . . . . . . . . . 16
SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
General Information . . . . . . . . . . . . . . . . . . . . . . . . 8 EGR VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
System Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 8 CANISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Component Location . . . . . . . . . . . . . . . . . . . . . . . 9 CATALYTIC CONVERTER . . . . . . . . . . . . . . . . 19
Positive Crankcase Ventilation System Check . . . . 9 General Information . . . . . . . . . . . . . . . . . . . . . . . 19
PCV Valve Check . . . . . . . . . . . . . . . . . . . . . . . . . 9
17-2 ENGINE AND EMISSION CONTROL - Engine Control System

ENGINE CONTROL SYSTEM

GENERAL INFORMATION
A cable-type accelerator mechanism and a
suspended-type pedal have been adopted.

SERVICE SPECIFICATIONS
Items Standard value

Accelerator cable play mm 1-2

Engine idle speed r/min 850 ± 50

ON-VEHICLE SERVICE
ACCELERATOR CABLE CHECK AND
ADJUSTMENT
1. Turn A/C and lamps OFF.
Inspect and adjust at no load.
2. Warm engine until stabilized at idle.
3. Confirm idle speed is at prescribed value.
Standard value: 850 ± 50 r/min
4. Stop engine (ignition switch OFF).
5. Confirm there are no sharp bends in accelerator cable.
6. Check inner cable for correct slack.
Standard value: 1 - 2 mm

Adjusting bolt 7. If there is too much slack or no slack, adjust play by

the following procedures.
(1) Loosen the adjusting bolt to release the cable.
(2) Move the plate until the inner cable play is at the
standard value, and then tighten the adjusting bolt
plate to the specified torque.
Tightening torque: 5.0 ± 1.0 N·m
 ENGINE AND EMISSION CONTROL - Engine Control System 17-3
ACCELERATOR CABLE AND PEDAL
REMOVAL AND INSTALLATION
Post-installation Operation
Accelerator Cable Adjustment (Refer to P.17-2.)

<L.H. drive vehicles>

5.0 ± 1.0 N·m
10 ± 2 N·m

10

11

1 9
5 12 ± 2 N·m
8
4
2
6
<R.H. drive vehicles> 6
7
5.0 ± 1.0 N·m

1 12
10 3

11
8
6
6 5
2
3
4 9
7
12 ± 2 N·m

12

Accelerator pedal removal steps Accelerator cable removal steps

1. Accelerator cable assembly connec- 1. Accelerator cable assembly
tion (Accelerator pedal side) (Accelerator pedal side)
2. Accelerator pedal assembly 10. Accelerator cable assembly connec-
3. Pedal pad tion (Throttle body side)
4. Push-on spring nut 11. Accelerator cable assembly
5. Accelerator arm assembly Accelerator pedal stopper removal
6. Bushing
7. Spring 12. Accelerator pedal stopper
8. Stopper
9. Accelerator pedal bracket
17-4 ENGINE AND EMISSION CONTROL - Emission Control System

EMISSION CONTROL SYSTEM

GENERAL INFORMATION
The emission control system consists of the following subsystems:
D Crankcase emission control system
D Evaporative emission control system
D Exhaust emission control system

Items Name Specification

Crankcase emission Positive crankcase ventilation (PCV) valve Variable flow type
control system (Purpose: HC reduction)

Evaporative emission Canister Equipped

control system Purge control solenoid valve Duty cycle type solenoid valve
Check valve Equipped
(Purpose: HC reduction)

Exhaust emission Air-fuel ratio control device - MPI system Oxygen sensor feedback type
control system (Purpose: CO, HC, NOx reduction)

Exhaust gas recirculation system Equipped

D EGR valve Single type
D EGR control solenoid valve Duty cycle type solenoid valve
(Purpose: NOx reduction)

Catalytic converter Monolith type

(Purpose: CO, HC, NOx reduction)

EMISSION CONTROL DEVICE REFERENCE TABLE

Related parts Crankcase Evaporative Air/fuel Catalytic Exhaust Reference
emission emission ratio converter gas page
control control control recirculation
system system system system

PCV valve × 17-9

Purge control solenoid valve × 17-12

Check valve × 17-12

MPI system component × × GROUP 13A

Catalytic converter × 17-19

EGR valve × 17-15

EGR control solenoid valve × 17-16

 ENGINE AND EMISSION CONTROL - Emission Control System 17-5
SERVICE SPECIFICATIONS
Items Standard value

Purge control solenoid valve coil resistance (at 20_C) Ω 30 - 34

EGR control solenoid valve coil resistance (at 20_C) Ω 29 - 35

VACUUM HOSE
VACUUM HOSE PIPING DIAGRAM

From
fuel tank
Canister
Check
valve

A P E
Fuel EGR control
pressure solenoid valve
Purge control
control solenoid
solenoid valve
valve Injector

Oxygen Fuel
sensor To pressure From
(front) fuel tank regulator fuel pump
PCV valve EGR
Air valve
inlet

Oxygen sensor (rear)

Three - way
catalytic converter
17-6 ENGINE AND EMISSION CONTROL - Emission Control System

VACUUM CIRCUIT DIAGRAM

Intake manifold Throttle body

To
combustion
chamber From air
cleaner

Vacuum
tank Purge control
solenoid valve

Fuel pressure
solenoid valve

Air by-pass valve

Fuel pressure
regulator EGR control
solenoid valve

Secondary air control

solenoid valve

Check valve

Brown

EGR valve
Secondary air
control valve

Canister

Air cleaner

Waste gate
actuator
Waste gate
solenoid valve
Vacuum hose colour
B: Black
G: Green
L: Light blue
R: Red
W: White
Y: Yellow
ENGINE AND EMISSION CONTROL - Emission Control System 17-7
VACUUM HOSE CHECK
1. Using the piping diagram as a guide, check to be sure
that the vacuum hoses are correctly connected.
2. Check the connection condition of the vacuum hoses,
(removed, loose, etc.) and check to be sure that there
are no bends or damage.

VACUUM HOSE INSTALLATION

1. When connecting the vacuum hoses, they should be
securely inserted onto the nipples.
2. Connect the hoses correctly, using the vacuum hose piping
diagram as a guide.
17-8 ENGINE AND EMISSION CONTROL - Emission Control System

CRANKCASE EMISSION CONTROL SYSTEM

GENERAL INFORMATION
The crankcase emission control system prevents crankcase ventilation (PCV) valve.
blow-by gases from escaping inside the crankcase The PCV valve lifts the plunger according to the
into the atmosphere. intake manifold vacuum so as to regulate the flow
Fresh air is sent from the air cleaner into the of blow-by gas properly. In other words, the blow-by
crankcase through the breather hose. The air gas flow is regulated during low load engine
becomes mixed with the blow-by gases inside the operation to maintain engine stability, while the flow
crankcase. is increased during high load operation to improve
The blow-by gas inside the crankcase is drawn the ventilation performance.
into the intake manifold through the positive

SYSTEM DIAGRAM

Breather hose
Ventilation hose

PCV valve
 ENGINE AND EMISSION CONTROL - Emission Control System 17-9
COMPONENT LOCATION
PCV valve

POSITIVE CRANKCASE VENTILATION SYSTEM

CHECK
1. Remove the ventilation hose from the PCV valve.
2. Remove the PCV valve from the rocker cover.
3. Reinstall the PCV valve at the ventilation hose.
4. Start the engine and run at idle.

5. Place a finger at the opening of the PCV valve and check

that vacuum of the intake manifold is felt.
NOTE
At this moment, the plunger in the PCV valve moves
back and forth.
6. If vacuum is not felt, clean the PCV valve or replace
it.
PCV valve

PCV VALVE CHECK

PCV valve 1. Insert a thin rod into the PCV valve from the side shown
in the illustration (rocker cover installation side), and move
the rod back and forth to check that the plunger moves.
2. If the plunger does not move, there is a clogging in the
PCV valve. In this case, clean or replace the PCV valve.
17-10 ENGINE AND EMISSION CONTROL - Emission Control System

EVAPORATIVE EMISSION CONTROL SYSTEM

GENERAL INFORMATION
The evaporative emission control system prevents When the engine coolant temperature is low or
fuel vapours generated in the fuel tank from when the intake air quantity is small (when the
escaping into the atmosphere. engine is at idle, for example), the engine control
Fuel vapours from the fuel tank flow through the unit turns the purge solenoid off to shut off the
fuel tank pressure control valve and vapour fuel vapour flow to the intake manifold.
pipe/hose to be stored temporarily in the canister. This does not only insure the driveability when the
When driving the vehicle, fuel vapours stored in engine is cold or running under low load but also
the canister flow through the purge solenoid and stabilize the emission level.
purge port and go into the intake manifold to be
sent to the combustion chamber.

SYSTEM DIAGRAM

Canister
Check Air flow sensor
valve
Engine coolant
Purge control temperature sensor
solenoid valve
(ON: Open) Intake air
temperature sensor
Barometric pressure
Control sensor
relay

Engine-ECU
Battery

COMPONENT LOCATION
Purge control solenoid valve

Alternator
Vacuum tank
 ENGINE AND EMISSION CONTROL - Emission Control System 17-11
PURGE CONTROL SYSTEM CHECK
Throttle body 1. Disconnect the vacuum hose (red stripe) from throttle
body and connect it to a hand vacuum pump.
2. Plug the nipple from which the vacuum hose was removed.
3. When the engine is cold or hot, apply a vacuum of 53
kPa, and check the condition of the vacuum.
When engine is cold
Red stripe (Engine coolant temperature: 40_C or less)
Plug
Engine condition Normal condition
At idle Vacuum is maintained
3,000 r/min

When engine is hot

(Engine coolant temperature: 80_C or higher)
Engine condition Normal condition
At idle Vacuum is maintained
3,000 r/min (within 3 Vacuum will leak.
minutes after engine starts)

Throttle body PURGE PORT VACUUM CHECK

1. Disconnect the vacuum hose (red stripe) from the throttle
body purge vacuum nipple and connect a hand vacuum
pump to the nipple.
2. Confirm that the vacuum is approximately constant
regardless of the engine rotation speed.
NOTE
Red stripe If vacuum changes, it is possible that the throttle body
purge port maybe clogged and require cleaning.

Vac-
uum

Engine speed (r/min)

17-12 ENGINE AND EMISSION CONTROL - Emission Control System

PURGE CONTROL SOLENOID VALVE CHECK

A
NOTE
When disconnecting the vacuum hose, always make a mark
so that it can be reconnected at original position.
1. Disconnect the vacuum hose from the solenoid valve.
2. Disconnect the harness connector.
3. Connect a hand vacuum pump to nipple (A) of the solenoid
valve (refer to the illustration at left).
Battery 4. Check airtightness by applying a vacuum with voltage
applied directly from the battery to the purge control
solenoid valve and without applying voltage.
Battery voltage Normal condition
Applied Vacuum leaks
Not applied Vacuum maintained
5. Measure the resistance between the terminals of the
solenoid valve.
Standard value: 30 - 34 Ω (at 20_C)

CHECK VALVE CHECK

Connect a hand vacuum pump to the check valve, apply
vacuum and check the airtightness.
Connected nipple colour Normal condition
Black Vacuum leaks
Brown Vacuum is maintained
 ENGINE AND EMISSION CONTROL - Emission Control System 17-13
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
GENERAL INFORMATION
The exhaust gas recirculation (EGR) system lowers the exhaust port of the cylinder head to the
the nitrogen oxide (NOx) emission level. When the combustion chamber through the intake manifold
air/fuel mixture combustion temperature is high, to decrease the air/fuel mixture combustion
a large quantity of nitrogen oxides (NOx) is temperature, resulting in reduction of NOx.
generated in the combustion chamber. Therefore, The EGR flow rate is controlled by the EGR valve
this system recirculates part of emission gas from so as not to decrease the driveability.

OPERATION
The EGR valve is being closed and does not D The engine coolant temperature is low.
recirculate exhaust gases under one of the following D The engine is at idle.
conditions. Otherwise, the EGR valve is opened D The throttle valve is widely opened.
and recirculates exhaust gases.

SYSTEM DIAGRAM
Throttle body

EGR control
solenoid valve

ON

EGR valve

Engine-ECU
Engine
control Air flow sensor
relay
Engine coolant
temperature sensor

Battery Crank angle sensor

Throttle position sensor

17-14 ENGINE AND EMISSION CONTROL - Emission Control System

COMPONENT LOCATION
EGR control solenoid valve EGR valve
Throttle body

Vacuum tank

Alternator

EXHAUST GAS RECIRCULATION (EGR)

CONTROL SYSTEM CHECK
1. Disconnect the vacuum hose (green stripe) from the EGR
control solenoid valve, and then connect a hand vacuum
pump via the three-way terminal.
2. When the engine is hot or cold, check the condition of
vacuum by racing the engine.
Three-way
terminal Alternator When engine is cold
Vacuum (Engine coolant temperature: 20_C or less)
tank EGR control
solenoid valve
Throttle valve Normal vacuum condition
Open quickly No vacuum will generate
(the same as barometric pressure.)

When engine is hot

(Engine coolant temperature: 80_C or higher)
Throttle valve Normal vacuum condition
Open quickly It will momentarily rise over 13 kPa

3. Disconnect the three-way terminal.

Green stripe 4. Connect the hand vacuum pump to the vacuum hose
(green stripe).
5. Check whether the engine stalls or the idling is unstable
when a vacuum of 27 kPa or higher is applied during
idling.

Alternator
Vacuum EGR control
tank solenoid valve
 ENGINE AND EMISSION CONTROL - Emission Control System 17-15
EGR VALVE CHECK
1. Remove the EGR valve and inspect for sticking, carbon
deposits, etc. If found, clean with a suitable solvent so
that the valve seats correctly.
2. Connect a hand vacuum pump to the EGR valve.
3. Apply 67 kPa of vacuum, and check that the vacuum
is maintained.
4. Apply a vacuum and check the passage of air by blowing
through one side of the EGR passage.
Vacuum Passage of air
5.3 kPa or less Air is not blown out
27 kPa or more Air is blown out
5. Replace the gasket, and tighten to the specified torque.
Tightening torque: 20 ± 2 N·m

Throttle body EGR PORT VACUUM CHECK

1. Disconnect the vacuum hose (White stripe) from the
throttle body EGR vacuum nipple and connect a hand
vacuum pump to the nipple.

White stripe

2. Start the engine and check vacuum remains fairly constant

after racing the engine.
NOTE
If the vacuum fluctuates, the throttle body EGR port may
Vacu- be clogged and need cleaning.
um

Engine speed (r/min)

17-16 ENGINE AND EMISSION CONTROL - Emission Control System

EGR CONTROL SOLENOID VALVE CHECK

B
NOTE
When disconnecting the vacuum hose, always make a mark
A so that it can be reconnected at original position.
1. Disconnect the vacuum hose (yellow stripe, green stripe,
C white stripe) from the solenoid valve.
2. Disconnect the harness connector.
Battery 3. Connect a hand vacuum pump to the nipple to which
the green-striped vacuum hose was connected.
4. Check airtightness by applying a vacuum with voltage
applied directly from the battery to the EGR control
solenoid valve and without applying voltage.

Battery voltage B nipple condition Normal condition

Not applied Open Vacuum maintained

Applied Open Vacuum leaks

Closed Vacuum maintained

5. Measure the resistance between the terminals of the

solenoid valve.
Standard value: 29 - 35 Ω (at 20_C)
 ENGINE AND EMISSION CONTROL - Emission Control System 17-17
EGR VALVE
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
Air Hose E Removal and Installation
(Refer to GROUP 15 - Inter Cooler.)

2
3

21 ± 4 N·m

Removal steps
1. Vacuum hose connection
2. EGR valve
3. EGR valve gasket
17-18 ENGINE AND EMISSION CONTROL - Emission Control System

CANISTER
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
D Air Pipe C, Air Hose D Removal and Installation (Refer to GROUP 15 - Inter Cooler.)
D Battery and Battery Tray Removal and Installation
D Air Cleaner Assembly Removal and Installation (Refer to GROUP 15 - Air Cleaner.)

2
4 1

5 9
6
3

Canister removal steps

1. Purge hose 6. Hose clamp
2. Check valve 7. Canister
3. Vapor hose 8. Fuel high pressure hose
4. Vent connector 9. Canister bracket assembly
5. Vapor hose
 ENGINE AND EMISSION CONTROL - Emission Control System 17-19
CATALYTIC CONVERTER
GENERAL INFORMATION
The three-way catalytic converter, together with When the mixture is controlled at stoichiometric
the closed loop air-fuel ratio control based on the air-fuel ratio, the three-way catalytic converter
oxygen sensor signal, oxidizes carbon monoxides provides the highest purification against the three
(CO) and hydrocarbons (HC) and reduces nitrogen constituents, namely, CO, HC and NOx.
oxides (NOx).

REMOVAL AND INSTALLATION

Pre-removal and Post-installation Operation
D Under Cover Removal and Installation (Refer to GROUP 51 - Front Bumper.)
D Crossmember Bar Removal and Installation (Refer to GROUP 32 - Engine Roll Stopper, Centermember.)

13 ± 2 N·m
49 ± 10 N·m
3

59 ± 10 N·m

1
13 ± 2 N·m

50 ± 5 N·m

Removal steps
1. Spring
2. Front exhaust pipe
3. Catalytic converter
NOTES