Lexus GS300/400 (2000 year). Manual - part 126

EC04Z–01

EC–14

–

EMISSION CONTROL (2JZ–GE)

THREE–WAY CATALYTIC CONVERTER (TWC) 
SYSTEM

1465

INSPECTION

1.

CHECK CONNECTIONS FOR LOOSENESS OR DAMAGE

2.

CHECK CLAMPS FOR WEAKNESS, CRACKS OR DAMAGE

3.

CHECK FOR DENTS OR DAMAGE

If any part of the protector is damaged or dented to the extent that it contacts the three–way catalytic convert-
er, repair or replace it.
4.

CHECK HEAT INSULATOR FOR DAMAGE

5.

CHECK FOR ADEQUATE CLEARANCE BETWEEN CATALYTIC CONVERTER AND HEAT INSU-
LATOR

EC050–04

B09011

–

EMISSION CONTROL (2JZ–GE)

THREE–WAY CATALYTIC CONVERTER (TWC) 
SYSTEM

EC–15

1466

REPLACEMENT

1.

REMOVE ENGINE COVER

2.

REMOVE AIR CLEANER INLET

3.

REMOVE AIR CLEANER, MAF METER AND INTAKE
AIR RESONATOR ASSEMBLY (See page 

EM–62

)

4.

DISCONNECT HEATED OXYGEN SENSORS FROM
EXHAUST MANIFOLD

(a)

Disconnect the 3 oxygen sensor connectors.

(b)

Disconnect the 2 oxygen sensors (bank 1 sensor 1, 2)
from the exhaust manifold.

5.

REMOVE FRONT EXHAUST PIPE (WITH REAR TWC)

(a)

Take out the front side of the floor carpet.

(b)

Disconnect the oxygen sensor connector.

(c)

Remove the 2 bolts and pipe support bracket.

(d)

Remove the 5 bolts, front exhaust pipe and 3 gaskets.

6.

REMOVE EXHAUST MANIFOLD (WITH FRONT TWC)

(a)

Using a 14 mm deep socket wrench, remove the 8 nuts,
the exhaust manifold and 2 gaskets.

(b)

Remove the heated oxygen sensor (bank 2 sensor 1)
form the exhaust manifold.

7.

REINSTALL NEX EXHAUST MANIFOLD (WITH FRONT
TWC)

(a)

Install the heated oxygen sensor (bank 2 sensor 1) to the
exhaust manifold.
Torque: 45 N·m (450 kgf·cm, 33 ft·lbf)

(b)

Install 2 new gaskets to the cylinder head.

(c)

Using a 14 mm deep socket wrench, install new exhaust
manifold with 8 new nuts. Uniformly tighten the nuts in
several passes.
Torque: 40 N·m (408 kgf·cm, 30 ft·lbf)

8.

REINSTALL FRONT EXHAUST PIPE (WITH REAR
TWC)

(a)

Reinstall new 3 gaskets, and front exhaust pipe with 5
bolts and support bracket.

(b)

Reinstall the pipe support bracket with 2 bolts.

9.

RECONNECT HEATED OXYGEN SENSORS TO EX-
HAUST MANIFOLD

(a)

Install the 2 oxygen sensors (bank 1 sensor 1, 2) to the
exhaust manifold.
Torque: 45 N·m (450 kgf·cm, 33 ft·lbf)

(b)

Connect the 3 oxygen sensor connectors.

10.

REINSTALL AIR CLEANER, MAF MATER AND INTAKE
AIR RESONATOR ASSEMBLY (See page 

EM–68

)

11.

REINSTALL AIR CLEANER INLET

12.

REINSTALL ENGINE COVER

EC04V–06

B08612

PCV Valve

VSV for EVAP

Front TWC

EVAP Service Port

Fill Check Line

Cutoff Valve

Charcoal Canister

Air Inlet Line

Vapor Pressure Sensor

Fuel Tank Cap

VSV for Vapor 
Pressure Sensor

Purge Line

EVAP Line

Vent Line

Air Drain Hose

Rear TWC

EC–2

–

EMISSION CONTROL (2JZ–GE)

PARTS LAYOUT AND SCHEMATIC DRAWING

1453

PARTS LAYOUT AND SCHEMATIC DRAWING

LOCATION

EC04W–06

B08613

VSV for Vapor Pressure Sensor

Purge Line

Air Inlet Line

Air Drain Hose

EVAP Line

Fuel Tank

Charcoal Canister

VSV for EVAP

Vapor Pressure Sensor

PCV Valve

Front TWC

Front TWC

Vent Line

Fuel Tank
Cap

EVAP
Service
Port

Rear TWC

–

EMISSION CONTROL (2JZ–GE)

PARTS LAYOUT AND SCHEMATIC DRAWING

EC–3

1454

DRAWING