Mitsubishi Pajero Pinin. Manual - part 166

ENGINE AND EMISSION CONTROL – 

Emission Control System <MPI>

EGR control solenoid valve

EGR valve

17-11

EXHAUST GAS RECIRCULATION (EGR) SYSTEM

GENERAL INFORMATION

The exhaust gas recirculation (EGR) system lowers
the nitrogen oxide (NOx) emission level. When the
air/fuel mixture combustion temperature is high, a
large quantity of nitrogen oxides (NOx) is generated
in the combustion chamber. Therefore, this system
recirculates part of emission gas from the exhaust

port of the cylinder head to the combustion chamber
through the intake manifold to decrease the air/fuel
mixture combustion temperature, resulting in
reduction of NOx.
The EGR flow rate is controlled by the EGR valve
so as not to decrease the driveability.

OPERATION

The EGR valve is being closed and does not
recirculate exhaust gases under one of the following
conditions. Otherwise, the EGR valve is opened
and recirculates exhaust gases.

D

The engine coolant temperature is low.

D

The engine is at idle.

D

The throttle valve is widely opened.

SYSTEM DIAGRAM

ON

OFF

EGR
control
solenoid
valve

Air flow sensor

Engine coolant

temperature sensor

Crank angle sensor

Control
relay

Engine-ECU

Battery

EGR valve

COMPONENT LOCATION

ENGINE AND EMISSION CONTROL – 

Emission Control System <MPI>

17-12

EXHAUST GAS RECIRCULATION (EGR)
CONTROL SYSTEM CHECK

1.

Disconnect the vacuum hose (green stripe) from the EGR
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.

When engine is cold
(Engine coolant temperature: 20

_

C or less)

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.

4.

Connect the hand vacuum pump to the EGR valve.

5.

Check whether the engine stalls or the idling is unstable
when a vacuum of 30 kPa or higher is applied during
idling.

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

5.0 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: 22 

±

5 N·m

Three-way
terminal

Vacuum hose
(Green stripe)

EGR valve

EGR valve

Plug

Vacuum hose
(Green stripe)

ENGINE AND EMISSION CONTROL – 

Emission Control System <MPI>

17-13

EGR PORT VACUUM CHECK

1.

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

2.

Start the engine and check that, after raising the engine
speed by racing the engine, purge vacuum raises according
to engine speed.

NOTE
If there is a problem with the change in vacuum, the throttle
body EGR port may be clogged and require cleaning.

EGR CONTROL SOLENOID VALVE CHECK

NOTE
When disconnecting the vacuum hose, always make a mark
so that it can be reconnected at original position.
1.

Disconnect the vacuum hose (yellow stripe, green stripe)
from the solenoid valve.

2.

Disconnect the harness connector.

3.

Connect a hand vacuum pump to the nipple (A) of the
solenoid valve (refer to the illustration at left).

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

Normal condition

Not applied

Vacuum maintained

Applied

Vacuum leaks

5.

Measure the resistance between the terminals of the
solenoid valve.

Standard value: 36 – 44 

Ω

 (at 20

_

C)

Vacuum

Engine speed (r/min)

A

B

Battery

ENGINE AND EMISSION CONTROL – 

Emission Control System <MPI>

17-14

CATALYTIC CONVERTER

REMOVAL AND INSTALLATION

1

2

4

3

5

50 

±

10

  N

·

m

50 

±

10

  N

·

m

50 

±

10

  N

·

m

50 

±

10

  N

·

m

50 

±

10

  N

·

m

50 

±

10

  N

·

m

13 

±

2

  N

·

m

Front catalytic converter removal
steps

1. Front pipe
2. Oxygen sensor (front)
3. Front catalytic converter

Catalytic converter removal steps

1. Front pipe
4. Oxygen sensor (rear)
5. Catalytic converter