catalytic converter TOYOTA CAMRY 2000 Service Repair Manual

CAMRY ± NEW FEATURES36
5S-FNE ENGINE
1. Description
The 5S-FNE engine is a new engine that uses CNG (Compressed Natural Gas) as fuel, which has been devel-
oped based on the 5S-FE gasoline engine.
The main component of natural gas is methane (CH
4), which has fewer carbous (C) than gasoline (mean mo-
lecular formula: C
7.5H13.4). Therefore, the amount of CO2 discharged by this engine is approximately 70%
that of the gasoline engine. Furthermore, this engine achieves low-emission operation by precisely controlled
air-fuel ratio and using special catalysts for the CNG application.
However, because the fuel is in the gaseous form, its volumetric efficiency is low, causing lower power output
if this fuel is used in the base engine.
Therefore, the 5S-FNE engine has adopted the following features: a high compression ratio, the intake valves
with early closed timing, the intake and exhaust valves with increased lift, a low back pressure muffler made
possible by the 2-way exhaust system, injectors for gaseous fuel, and a catalytic converter designed exclu-
sively for CNG application. At the same time, precision air-fuel ratio control is effected through the use of
the air-fuel ratio sensor* and the heater oxygen sensor, thus achieving the level of performance that is equiva-
lent to the base engine. Moreover, this engine realizes extremely low emissions and restoring engine torque.
*: Already adopted on the California specification 5S-FE engine.

Specifications 
Item5S-FNE Engine5S-FE Engine
No. of Cyls. & Arrangement4-Cylinder, In-Line
Valve Mechanism16-Valve DOHC,
Belt & Gear Drive
Combustion CamberPentroof Type
ManifoldsCross-Flow
Fuel SystemSFI
Displacement cm3 (cu.in.)2164 (312.0)
Bore x Stroke mm (in.)87.0 x 91.0 (3.43 x 3.58)
Compression Ratio11.0 : 19.5 : 1
Max. Output [SAE-NET]88 kW @ 5200 rpm
(118 HP @ 5200 rpm)
101 kW @ 5200 rpm
(136 HP @ 5200 rpm)
97 kW @ 5200 rpm*
(133 HP @ 5200 rpm)*
Max. Torque [SAE-NET]178 N.m @ 2400 rpm
(131 ft-lbf @ 2400 rpm)
203 N.m @ 4400 rpm
(150 ft-lbf @ 4400 rpm)
201 N
.m @ 4400 rpm*
(148 ft-lbf @ 4400 rpm)*
IntakeOpen3 BTDC
Valve
IntakeClose38 ABDC43 ABDCValve
Timing
ExhaustOpen45 BBDCExhaustClose3 AT D C
Fuel Octane Number RON13091
Oil GradeAPI SJ EC or ILSAC
*: California Specification Models

CAMRY ± NEW FEATURES 38
2. Features of 5S-FNE Engine
Features of the 5S-FNE engine are listed below.
Item
Features
Performance
High compression ratio is used.
High lift camshaft is used.
Low back pressure muffler is used.
Fuel Economy
High compression ratio is used.
Valve spring load has been reduced.
Low-friction. TiN (titanium nitride) coated valve lifters has been adopted.
Low Emission
A fuel injection system containing gas injectors has been adopted.
Because the fuel is in the gaseous state, it does not come in contact with
the wall surface, making optimal air-fuel ratio control possible
immediately after the engine has been started.
Precision air-fuel ratio feedback control that uses an air-fuel ratio sensor
and a heated oxygen sensor has been adopted.
Two catalytic converters designed exclusively for the natural gas engine
have been adopted: the WU-TWC (Warm Up Three-Way Catalytic
Converter) and the TWC (Three-Way Catalytic Converter).
Other Features
Highly rigid pistons have been adopted to accommodate the high
compression ratio.
A CNG (Compressed Natural Gas) pressure regulator that precisely
regulates the CNG has been adopted.
A large-bore delivery pipe and fuel hose with minimal internal conduit
resistance have been adopted.
The electro magnetic fuel shutoff valve is added on the delivery pipe.
A fuel pressure sensor that corrects the fuel injection volume and a fuel
temperature sensor have been provided on the delivery pipe.
The starting performance of the engine at low temperatures has been
ensured by increasing the volume of the airflow of the IAC (Idle Air
Control).
Materials that excel in wear resistance have been adopted on the valves
and valve seats for both the intake and exhaust.
Rust-resistant spark plugs have been adopted.
Aluminum lining and carbon fiber have been adopted in the fuel tank.
For the fuel gauge, a fuel tank fuel temperature sensor and a fuel pipe fuel
pressure sensor have been adopted.

3
CAMRY ± NEW FEATURES
167CN05
WU-TWC
167CN06
TWCSub MufflerMain Muffler41
5. Intake and Exhaust System
Throttle Body
The throttle body is basically the same as that of the 5S-FE engine. However, to ensure the starting perfor-
mance at low temperatures, the air passage for the IAC (Idle Air Control) has been increased on the 5S-FNE
engine. The IAC valve is a 1-coil type with a built-in driver.
Exhaust Manifold
As in the California specification 5S-FE engine,
the stainless steel exhaust manifold and WU-
TWC (Warm Up Three-Way Catalytic Convert-
er) have been integrated to improve the warm-up
performance of TWC, thus reducing exhaust
emissions.
However, the 5S-FNE engine uses a catalytic
converter that has been designed exclusively for
the CNG application, in which the loading of the
noble metal has been increased.
Exhaust Pipe
1) General
To secure sufficient luggage compartment capacity, the main muffler has been relocated below the rear
seat. Furthermore, the muffler capacity has been increased.
A 2-way exhaust control system has been adopted to improve engine performance and reduce the exhaust
noise.
Similar to the WU-TWC, the TWC (Three-Way Catalytic Converter) has been designed exclusively for
the CNG application, in which the loading of the noble metal has been increased.

10. SEPARATE EXHAUST MANIFOLD AND WARM UP
THREE±WAY CATALYTIC CONVERTER
Remove the following parts:
(1) 3 bolts
(2) Manifold lower heat insulator
(3) 8 bolts
(4) 2 WU±TWC heat insulators 9. REMOVE EXHAUST MANIFOLD AND WARM UP
THREE±WAY CATALYTIC CONVERTER ASSEMBLY
(a) Disconnect the main oxygen and sub oxygen sensor
connectors.
(b) Remove the 4 bolts and upper heat insulator.
(e) Remove the 6 nuts, the exhaust manifold and WU ±
TWC assembly. (c) Remove the bolt, nut and No. 1 manifold stay.
(d) Remove the bolt, nut and manifold stay.
± 5S±FE ENGINEENGINE MECHANICALEG1±43

31. ASSEMBLE EXHAUST MANIFOLD AND WARM UP
THREE±WAY CATALYTIC CONVERTER
Assemble the following parts:
(1) WU±TWC
(2) Cushion
(3) Retainer
(4) Gasket
(5) Exhaust manifold
(6) 3 bolts and 2 nuts
Torque: 29 N±m (300 kgf±cm, 22 ft±lbf)
(c) Connect the following connectors:
(1) Engine coolant temperature sender gauge con±
nector
(2) Engine coolant temperature sensor connector
29. CONNECT ENGINE WIRE (FOR OXYGEN SENSORS)
TO ENGINE HANGER
30. CONNECT OIL PRESSURE SWITCH CONNECTOR
32. INSTALL EXHAUST MANIFOLD AND WARM UP
THREE±WAY CATALYTIC CONVERTER
ASSEMBLY
(a) Install a new gasket, the exhaust manifold and WU ±
TWC assembly with the 6 nuts. Uniformly tighten the
nuts in several passes.
Torque: 49 N±m (540 kgf±cm, 36 ft±lbf)
(7) 2 converter heat insulators
(8) 8 bolts
(9) Manifold lower heat insulator
(10) 3 bolts
± 5S±FE ENGINEENGINE MECHANICALEG1±80

Reduces blow±by gas (HC)
Reduces evaporative HC
Reduces NOx
Reduces C0, HC and NOx
Regulates all engine conditions for reduction
of exhaust emissions. Positive crankcase ventilation
Fuel evaporative emission control
Exhaust gas recirculation
Three±way catalytic converter
*Multiport fuel injection/Sequential
multiport fuel injection
PREPARATION
SST (SPECIAL SERVICE TOOLS)
EMISSION CONTROL SYSTEMS
º For inspection and repair of the MFI/SFI system, refer to MFI/SFI Section.
SSM (SPECIAL SERVICE MATERIALS)
08833±00070 Adhesive 1311,
THREE BOND 1311 or equivalent
RECOMMENDED TOOLS
SYSTEM PURPOSE
09082±00050 TOYOTA Electrical Tester SetPCV
EVAP
EG R
TWC
MFI/SFI
09843±18020 Diagnosis Check Wire
EQUIPMENT
Torque wrench
Vacuum gaugeAbbreviation
Thermometer
Tachometer
Purpose
system
Heater
¿¿VTVV
TVV
± 5S±FE ENGINEEMISSION CONTROL SYSTEMSEG1±145

EXHAUST PIPE ASSEMBLY INSPECTION
1. CHECK CONNECTIONS FOR LOOSENESS OR
DAMAGE
2. CHECK CLAMPS FOR WEAKNESS, CRACKS OR
DAMAGE
THREE±WAY CATALYTIC CONVERTER
INSPECTION
TWC:
CHECK FOR DENTS OR DAMAGE
If any part of protector is damaged or dented to the
extent that it contacts the TWC, repair or replace it.
To reduce C0, HC end NOx emissions, they are oxidized, reduced and converted to carbon dioxide (CO2), water (H20)
and nitrogen (N
2) by the catalyst.
THREE±WAY CATALYTIC CONVERTER (TWC) SYSTEM
Exhaust Port
Exhaust Gas WU±TWC
TWC
± 5S±FE ENGINEEMISSION CONTROL SYSTEMSEG1±158

THREE±WAY CATALYTIC CONVERTER
REPLACEMENT
WU±TWC:
1. DISCONNECT NEGATIVE (±) TERMINAL CABLE
FROM BATTERY
CAUTION: Work must be started after 90 seconds from
the time the ignition switch is turned to the 'LOCK'
position and the negative (±) terminal cable is discon±
nected from the battery.
2. REMOVE FRONT EXHAUST PIPE
(a) Loosen the 2 bolts, and disconnect the bracket.
(b) Remove the 2 bolts and nuts holding the front exhaust
pipe to the center exhaust pipe.
(c) Using a 14 mm deep socket wrench, remove the 3
nuts holding the front exhaust pipe to the WU±TWC.
(d) Remove the front exhaust pipe and gaskets.HEAT INSULATOR INSPECTION
TWC:
1. CHECK HEAT INSULATOR FOR DAMAGE
2. CHECK FOR ADEQUATE CLEARANCE BETWEEN
THREE ± WAY CATALYTIC CONVERTER AND
HEAT INSULATOR
3. REMOVE WARM UP THREE ± WAY CATALYTIC
CONVERTER
(a) Check that the WU±TWC is cool.
(b) Disconnect the sub oxygen sensor connector.
(c) Remove the bolt, nut and No. 1 manifold stay.
± 5S±FE ENGINEEMISSION CONTROL SYSTEMSEG1±159

(e) Remove the 3 bolts, 2 nuts, WU ±TWC, gasket, re±
tainer and cushion.
(f) Remove the 8 bolts and 2 heat insulators from the
WU ±TWC.
4. REINSTALL WARM±UP THREE±WAY
CATALYTIC CONVERTER
(a) Install the 2 heat insulators to a new WU ±TWC with
the 8 bolts.
(c) Install the WU±TWC with the 3 bolts and 2 new nuts.
Torque: 29 N±m (300 kgf±cm, 22 ft±lbf)
(b) Place new cushion, retainer and gasket on the WU±
TWC. (d) Remove the bolt, nut and manifold stay.
± 5S±FE ENGINEEMISSION CONTROL SYSTEMSEG1±160

TWC:
1. REMOVE FRONT EXHAUST PIPE (THREE ± WAY
CATALYTIC CONVERTER)
(a) Loosen the 2 bolts, and disconnect the bracket.
(b) Remove the 2 bolts and nuts holding the front exhaust
pipe to the center exhaust pipe.
(c) Using a 14 mm deep socket wrench, remove the 3
nuts holding the front exhaust pipe to the WU±TWC.
(d) Remove the front exhaust pipe and gasket.
2. REINSTALL FRONT EXHAUST PIPE (THREE±WAY
CATALYTIC CONVERTER)
(a) Place 2 new gaskets on the front and rear of the front
exhaust pipe.
(b) Temporarily install the 2 bolts and 2 new nuts holding
the front exhaust pipe to the center exhaust pipe.
(c) Using a 14 mm deep socket wrench, install the 3 new
nuts holding the front exhaust pipe to the WU ±TWC.
Torque: 412 N±m (630 kgf±cm, 46 ft±lbf)
(d) Tighten the 2 bolts and nuts holding the front exhaust
pipe to the center exhaust pipe.
Torque: 58 N±m (570 kgf±cm, 41 ft±lbf)
(e) Install the bracket with the 2 bolts.
± 5S±FE ENGINEEMISSION CONTROL SYSTEMSEG1±162