2000 LEXUS GS400 sensor

B08609
N´m (kgf´cm, ft´lbf) : Specified torque

Non±reusable part
44 (440, 32)
Gasket


Gasket

Front Exhaust Pipe
(with Rear TWC)
44 (440, 32)
44 (440, 32)
Pipe Support Bracket Floor Carpet Under CoverHeated Oxygen
Sensor Connector
TWC
± EMISSION CONTROL (2JZ±GE)THREE±WAY CATALYTIC CONVERTER (TWC)
SYSTEMEC±13
1464 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

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

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

B06842
Air
Air Inlet Line Hose
B06803
Push
PinchPinch
A A
B06791
B06792Air
Purge Port
Air Drain Port
EVAP Port
Cap
Vent Port
EC±10
± EMISSION CONTROL (2JZ±GE)EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1461 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
7. CHECK AIR INLET LINE
(a) Disconnect the air inlet line hose from the charcoal canis-
ter.
(b) Check that there is ventilation in the air inlet line.
(c) Reconnect the air inlet line hose to the charcoal canister.
8. REMOVE CHARCOAL CANISTER ASSEMBLY
(a) Disconnect the RH rear drive shaft from the differential.
(See page SA±52)
(b) Remove the charcoal canister assembly.
(1) Disconnect the vapor pressure sensor connector.
(2) Disconnect the VSV connector for vapor pressure
sensor.
(3) Disconnect the purge line hose, EVAP line hose
and air inlet line from the charcoal canister.
(4) Disconnect the vent line hose from the charcoal
canister.
Push the connector deep inside, pinch portion A,
and pull out the connector.
(5) Disconnect the air drain hose from the chanister
tank.
(6) Remove the 3 nuts and the charcoal canister as-
sembly.
9. INSPECT CHARCOAL CANISTER
(a) Visually check the charcoal canister for cracks or dam-
age.
(b) Inspect the charcoal canister operation.
(1) Plug the vent port with a cap.
(2) While holding the purge port closed, blow air (1.76
kPa, 18 gf/cm
2, 0.26 psi) into the EVAP port and
check that air flows from the air drain port.

B06793Air
Purge Port
EVAP
Port
Air Drain PortAir Inlet Port
B06794
Vacuum
Purge Port
Air Inlet Port
B06795Vacuum
Purge Port
EVAP
Port Air Inlet Port
± EMISSION CONTROL (2JZ±GE)EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC±11
1462 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(3) While holding the purge port and the air drain port
closed, blow air (1.76 kPa, 18 gf/cm
2, 0.26 psi) into
the EVAP port and check that air does not flow from
the air inlet port.
(4) Apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg)
to the purge port, check that the vacuum does not
decrease when the air inlet port is closed, and
check that the vacuum decreases when the air inlet
port is released.
(5) While holding the air inlet port closed, apply vacuum
(3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the EVAP port
and check that air flows into the purge port.
If operation is not as specified, replace the charcoal canister.
10. INSPECT VSV FOR EVAP
(See page SF±52)
11. INSPECT VSV FOR VAPOR PRESSURE SENSOR
(See page SF±57)
12. INSPECT VAPOR PRESSURE SENSOR
(See page SF±61)
13. REINSTALL CHARCOAL CANISTER ASSEMBLY
(a) Install the charcoal canister assembly.
(b) Connect the RH rear drive shaft to the differential.
(See page SA±59)

EM±2
± ENGINE MECHANICAL (2JZ±GE)CO/HC
1356 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.
(a) Check heated oxygen sensors operation.
(See page DI±44)
(b) See the table below for possible causes, and then inspect
and correct the applicable causes if necessary.
HCCOPhenomenonCauses
HighNormalRough idle1. Faulty ignitions:

Incorrect timing

Fouled, shorted or improperly gapped plugs

Open or crossed high±tension cords
2. Incorrect valve clearance
3. Leaky intake and exhaust valves
4. Leaky cylinder
HighLowRough idle
(Fluctuating HC reading)1. Vacuum leaks:

PCV hose

Intake manifold

Throttle body

Cylinder head gasket
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)1. Restricted air filter
2. Plugged PCV valve
3. Faulty SFI systems:

Faulty pressure regulator

Faulty ECM

Faulty injector

Faulty throttle position sensor

Faulty mass air flow meter