LEXUS GS400 2000 Service Repair Manual

EC04Z±01
EC±14± EMISSION CONTROL (2JZ±GE)THREE±WAY CATALYTIC CONVERTER (TWC)
SYSTEM
1465 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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)
SYSTEMEC±15
1466 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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 LineCutoff ValveCharcoal 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 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
PARTS LAYOUT AND SCHEMATIC DRAWING
LOCATION

EC04W±06
B08613
VSV for Vapor Pressure Sensor
Purge Line
Air Inlet LineAir Drain Hose
EVAP Line
Fuel Tank Charcoal Canister VSV for EVAPVapor 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 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DRAWING

EC04X±05
B02023
PCV Valve
P02006Cylinder Head SideClean Hose
P02477
Intake Air
Connector Side
B02817
Side
Line
55° EC±4
± EMISSION CONTROL (2JZ±GE)POSITIVE CRANKCASE VENTILATION (PCV)
SYSTEM
1455 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
POSITIVE CRANKCASE
VENTILATION (PCV) SYSTEM
INSPECTION
1. REMOVE ENGINE COVER
Remove 4 nuts and engine cover.
2. REMOVE PCV VALVE
(a) Disconnect the PCV hose from the PCV valve.
(b) Remove the PCV valve.
3. INSTALL CLEAN HOSE TO PCV VALVE
4. INSPECT PCV VALVE OPERATION
(a) Blow air into the cylinder head side, and check that air
passes through easily.
CAUTION:

Do not suck air through the valve.

Petroleum substances inside the valve are harmful.
(b) Blow air into the intake air connector side, and check that
air passes through with difficulty.
If operation is not as specified, replace the PCV valve.
5. REMOVE CLEAN HOSE FROM PCV VALVE
6. REINSTALL PCV VALVE
The port faces in the direction indicated in the illustration.

S00601
± EMISSION CONTROL (2JZ±GE)POSITIVE CRANKCASE VENTILATION (PCV)
SYSTEMEC±5
1456 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
7. VISUALLY INSPECT HOSES, CONNECTIONS
AND GASKETS
Check for cracks, leaks or damage.
8. REINSTALL ENGINE COVER
Install the engine cover with the 4 nuts.

EC053±05
B06731
RH Rear Drive Shaft
Rear Suspension
Member Brace
Charcoal Canister AssemblyVapor Pressure
Sensor Connector
EVAP HoseVSV Connector
for Vapor Pressure
Sensor
Air Inlet Hose
83 (850, 61)
50 (510, 37)
Purge Hose
N´m (kgf´cm, ft´lbf) : Specified torque
Air Drain Hose
Vent Line Hose Canister Tank
EC±6
± EMISSION CONTROL (2JZ±GE)EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1457 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
COMPONENTS

EC0BD±02
B02709
Gasket
Vacuum
Valve Pressure
Valve
B06544
Vacuum
Gauge
B01982
LEXUS Hand±Held Tester
DLC 3
B06548Battery
± EMISSION CONTROL (2JZ±GE)EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC±7
1458 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT LINES AND CONNECTORS
Visually check for loose connections, sharp bends or damage.
2. INSPECT FUEL TANK FILLER PIPE
Visually check for deformation, cracks or fuel leakage.
3. VISUALLY INSPECT FUEL TANK CAP
Check if the cap and/or gasket are deformed or damaged.
If necessary, repair or replace the cap.
4. INSPECT EVAP SYSTEM LINE
(a) Warm up the engine and stop the engine.
Allow the engine to warm up to normal operating tempera-
ture.
(b) Install a vacuum gauge (EVAP control system test equip-
ment vacuum gauge) to the EVAP service port on the
purge line.
(c) LEXUS Hand±Held Tester:
Forced driving of the VSV for the EVAP.
(1) Connect a LEXUS hand±held tester to the DLC3.
(2) Start the engine.
(3) Push the LEXUS hand±held tester main switch ON.
(4) Use the ACTIVE TEST mode on the LEXUS hand±
held tester to operate the VSV for the EVAP.
(d) If you have no LEXUS Hand±Held Tester:
Forced driving of the VSV for the EVAP.
(1) Disconnect the VSV connector for the EVAP.
(2) Connect the positive (+) and negative (±) leads from
the battery to the VSV terminals for the EVAP.
(3) Start the engine.

B06545
B06743Hose ClipperAir Drain Hose
B06546
Pressure
Gauge
Pressure EC±8
± EMISSION CONTROL (2JZ±GE)EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1459 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) Check the vacuum at idle.
Vacuum:
Maintain at 0.368 ± 19.713 in.Hg (5 ± 268 in.Aq) for over
5 seconds
HINT:
If the vacuum does not change, you can conclude that the hose
connecting the VSV to the service port has come loose or is
blocked, or the VSV is malfunctioning.
(f) LEXUS Hand±Held Tester:
Conclude forced driving of the VSV for the EVAP.
(1) Stop the engine.
(2) Disconnect the LEXUS hand±held tester from the
DLC3.
(g) If you have no LEXUS Hand±Held Tester:
Conclude forced driving of the VSV for the EVAP.
(1) Stop the engine.
(2) Disconnect the positive (+) and negative (±) leads
from the battery from the VSV terminals for the
EVAP.
(3) Connect the VSV connector for the EVAP.
(h) Disconnect the vacuum gauge from the EVAP service
port on the purge line.
(i) Connect a pressure gauge to the EVAP service port on
the purge line.
(j) Check the pressure.
(1) Close off the air drain hose at the marked position
of the canister with a hose clipper or similar instru-
ment.
(2) Add the pressure (13.5 ± 15.5 in.Aq) from the EVAP
service port.
Pressure:
2 minutes after the pressure is added, the gauge
should be over 7.7 ± 8.8 in.Aq.
HINT:
If you can't add pressure, you can conclude that the hose con-
necting the VSV
canister
fuel tank has slipped off or the
VSV is open.

B06547
Fuel Tank Cap
B06840
AirDisconnect
EVAP Line Hose
B06841Air
Disconnect
Plug
Disconnect
EVAP Line Hose
Purge Line
Hose
Purge Port
± EMISSION CONTROL (2JZ±GE)EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC±9
1460 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(3) Check if the pressure decreases when the fuel tank
cap is removed while adding pressure.
HINT:
If the pressure does not decrease when the filler cap is re-
moved, then you can conclude that the hose connecting the
service port to the fuel tank is blocked, etc.
(k) Disconnect the pressure gauge from the EVAP service
port on the purge line.
5. CHECK AIRTIGHTNESS IN FUEL TANK AND FILLER
PIPE
(a) Disconnect the EVAP line hose from the charcoal canister
side and then pressurize and make the internal pressure
in the fuel tank 4 kPa (41 gf/cm
2, 0.58 psi).
(b) Check that the internal pressure of the fuel tank can be
hold for 1 minute.
(c) Check the connected portions of each hose and pipe.
(d) Check the installed parts on the fuel tank.
If there is no abnormality, replace the fuel tank and filler pipe.
(e) Reconnect the EVAP line hose to the charcoal canister.
6. INSPECT FUEL CUTOFF VALVE AND FILL CHECK
VA LV E
(a) Disconnect the purge line hose and EVAP line hose from
the charcoal canister.
(b) Disconnect the air drain hose from the canister tank, and
plug its.
(c) Pressurize 4 kPa (41 gf/cm
2, 0.58 psi) to the purge port
and check that there is ventilation through the EVAP line
hose.
HINT:
In the condition that the fuel fuel is full, as the float value of the
fill check valve is closed and has no ventilation, it is necessary
to check the fuel amount (volume).
(d) Check if there is any struck in the vent line hose and EVAP
line hose.
If there is no stuck in hoses, replace the fuel cutoff valve and fill
check valve.
(e) Reconnect the purge line hose and EVAP line hose to the
charcoal canister.
(f) Reconnect the air drain hose to the canister tank.