2000 LEXUS GS400 catalytic converter

EC00B±05
± EMISSION CONTROL (2JZ±GE)EMISSION CONTROL SYSTEM
EC±1
1452 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
EMISSION CONTROL SYSTEM
PURPOSE
The emission control systems are installed to reduce the amount of CO, HC and NOx exhausted from the
engine (3) and (4)), to prevent the atmospheric release of blow±by gas±containing HC (1) and evaporated
fuel containing HC being released from the fuel tank (2).
The function of each system is shown in these table.
SystemAbbreviationFunction
(1) Positive Crankcase Ventilation
(2) Evaporative Emission Control
(3) Three±Way Catalytic Converter
(4) Sequential Multiport Fuel Injection *PCV
EVAP
TWC
SFIReduces blow±by gas (HC)
Reduces evaporated HC
Reduces CO, HC and NOx
Injects a precisely timed, optimum amount of fuel for reduced exhaust
emissions
Remark: * For inspection and repair of the SFI system, refer to the SF section this manual.

EC0DF±01
B01589
Air Cleaner, MAF Meter
and Intake Air Resonator
AssemblyPCV Hose
PS Air Hose
Air Cleaner Inlet MAF Meter Connector
Heated Oxygen Sensor
(Bank 1 Sensor 1)EVAP Hose

Gasket
Exhaust Manifold (with Front TWC)
Pipe Support Bracket
N´m (kgf´cm, ft´lbf)

Non±reusable partWire Grommet
Front Exhaust Pipe
: Specified torque
Heated Oxygen Sensor
(Bank 2 Sensor 1)
Heated Oxygen Sensor
(Bank 1 Sensor 2)

Gasket
40 (408, 30)
x 8
45 (450, 32)
44 (440, 32)
Engine Wire Clamp
Case Clamp

Clamp
44 (440, 32)
EC±12± EMISSION CONTROL (2JZ±GE)THREE±WAY CATALYTIC CONVERTER (TWC)
SYSTEM
1463 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
THREE±WAY CATALYTIC CONVERTER (TWC) SYSTEM
COMPONENTS

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)

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

± INTRODUCTIONFOR ALL OF VEHICLES
IN±17
17 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
3. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two±way radios and cellular telephones, observe
the following precautions.
(1) Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the ve-
hicle's electronic systems. For details about ECU and sensors locations, refer to the section on
the applicable component.
(3) Avoid winding the antenna feeder together with other wiring as much as possible, and also avoid
running the antenna feeder parallel with other wire harnesses.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communications system.
4. FOR USING OBD II SCAN TOOL OR LEXUS HAND±HELD TESTER
CAUTION:
Observe the following items for safety reasons:

Before using the OBD II scan tool or LEXUS hand±held tester, the OBD II scan tool's instruction
book or LEXUS hand±held tester's operator manual should be read thoroughly.

Be sure to route all cables securely when driving with the OBD II scan tool or LEXUS hand±held
tester connected to the vehicle. (i.e. Keep cables away from feet, pedals, steering wheel and
shift lever.)

Two persons are required when test driving with the OBD II scan tool or LEXUS hand±held tes-
ter, one person to drive the vehicle and the other person to operate the OBD II scan tool or LEX-
US hand±held tester.

IN04Q±07
IN±36
± INTRODUCTIONTERMS
36 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti±Lock Brake System
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir±Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
A/TAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi±Level
B/SBore±Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching Valve
Calif.California
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve

IN±42
± INTRODUCTIONTERMS
42 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) HO2S
Heated Oxygen SensorHeated Oxygen Sensor (HO2S)
IACIdle Air ControlIdle Speed Control (ISC)
IATIntake Air TemperatureIntake or Inlet Air Temperature
ICMIgnition Control Module±
IFIIndirect Fuel InjectionIndirect Injection (IDL)
IFSInertia Fuel±Shutoff±
ISCIdle Speed Control±
KSKnock SensorKnock Sensor
MAFMass Air FlowAir Flow Meter
MAPManifold Absolute PressureManifold Pressure
Intake Vacuum
MCMixture Control
Electric Bleed Air Control Valve (EBCV)
Mixture Control Valve (MCV)
Electric Air Control Valve (EACV)
MDPManifold Differential Pressure±
MFIMultiport Fuel InjectionElectronic Fuel Injection (EFI)
MILMalfunction Indicator LampCheck Engine Lamp
MSTManifold Surface Temperature±
MVZManifold Vacuum Zone±
NVRAMNon±Volatile Random Access Memory±
O2SOxygen SensorOxygen Sensor, O2 Sensor (O2S)
OBDOn±Board DiagnosticOn±Board Diagnostic System (OBD)
OCOxidation Catalytic ConverterOxidation Catalyst Convert (OC), CCo
OPOpen LoopOpen Loop
PAIRPulsed Secondary Air InjectionAir Suction (AS)
PCMPowertrain Control Module±
PNPPark/Neutral Position±
PROMProgrammable Read Only Memory±
PSPPower Steering Pressure±
PTOXPeriodic Trap OxidizerDiesel Particulate Filter (DPF)
Diesel Particulate Trap (DPT)
RAMRandom Access MemoryRandom Access Memory (RAM)
RMRelay Module±
ROMRead Only MemoryRead Only Memory (ROM)
RPMEngine SpeedEngine Speed
SCSuperchargerSupercharger
SCBSupercharger BypassE±ABV
SFISequential Multiport Fuel InjectionElectronic Fuel Injection (EFI), Sequential Injection
SPLSmoke Puff Limiter±
SRIService Reminder Indicator±
SRTSystem Readiness Test±
STScan Tool±
TBThrottle BodyThrottle Body
TBIThrottle Body Fuel InjectionSingle Point Injection
Central Fuel Injection (Ci)
TCTurbochargerTurbocharger
TCCTorque Converter ClutchTorque Converter