Emission Control – V6 Engine Page 6E1–1
Page 6E1–1
Section 6E1
Emission Control – V6 Engine
ATTENTION
Before performing any Service Operation or other procedure described in this Section, refer to Section 00
Warnings, Cautions and Notes for correct workshop practices with regard to safety and/or property damage.
1 General Information............................................................................................................................... 2
1.1 Euro 2 Emission Standards...................................................................................................................................2
1.2 Changes to Vehicle................................................................................................................................................3
1.3 Emission Control....................................................................................................................................................4
2 Service Operations................................................................................................................................ 5
2.1 References..............................................................................................................................................................5
Heated Oxygen Sensors (HO2S)............................................................................................................................5
Emission Control – V6 Engine Page 6E1–2
Page 6E1–2
1 General Information
With the following exceptions, MY 2004 WK Series Emission Control – V6 Engine information carries over from MY 2003
VY Series vehicles. For information not contained within this Section, refer to Section 6E1 Emission Control – V6 Engine
in the MY 2003 VY and V2 Series Service Information.
The vehicle has been configured to comply with the Euro 2 vehicle emission standards.
1.1 Euro 2 Emission Standards
Euro 2 is a European standard setting vehicle emission targets to encourage vehicle manufacturers to reduce harmful
vehicle emissions such as carbon monoxide (CO), hydrocarbons (HC) and the various oxides of nitrogen (NOx).
Australian Design Rule 79/00 implements the 'Euro 2' exhaust and evaporative emissions requirements for light vehicles
to reduce air pollution. The following tests are prescribed:
• average tailpipe emissions after a cold start,
• carbon monoxide emission at idling speed,
• emission of crankcase gases,
• evaporative em is sion s, and
• durability of pollution-control devices.
Emission Control – V6 Engine Page 6E1–3
Page 6E1–3
1.2 Changes to Vehicle
MY2004 WK vehicles have been configured to comply with Euro 2 vehicle emission standards by refinements in engine
calibration and optimisati on of the ex haust sy ste m cata ly tic c onverter configuratio ns.
As optimum catalytic converter performance is reached above 500°C, a close coupling of the catalytic converter with the
exhaust manifo ld ensures that, upon engine startup, the engine ex haust gas es can heat the cataly tic conv erter to an
optimum operating temperature in as short a time as possible.
The major modification made to that used on the MY 2003 VY V6 exhaust system from previous Series vehicles includes
the use of new heated oxygen sensors, two close-coupled catalytic converters, on-pipe heat shielding and reconfigured
front to intermediate exhaust assemblies. The oxygen sensors are moved towards the engine and are positioned
between the exhaust manifold and the catalytic converter.
Emission Control – V6 Engine Page 6E1–4
Page 6E1–4
1.3 Emission Control
The Powertrain Control Module (PCM) controls the air-fuel mixture delivered to the engine. Oxygen sensors are used to
provide feedback to the PCM to ensure that an ideal air-fuel ratio is maintained.
Exhaust emissions contain a variety of gases that include water vapour (H2O) , car bon dioxide (CO2), carbon monoxide
(CO), hydrocarbons (HC) and various oxides of nitrogen (NOx). Three-way catalytic converters incorporated along the
front exhaust pipe assemblies convert the gaseous pollutants carbon monoxide (CO), hydrocarbons (HC) and the
various ox ides of nitrogen (NO x) to less toxic gases that include water (H2O), carbon dioxide (CO2) and nitrogen (N2).
The exhaust system fitted to a particular vehicle depends on the engine type and model specifications.
For further information on the revised exhaust system, refer to Section 8B Exhaust System.
Emission Control – V6 Engine Page 6E1–5
Page 6E1–5
2 Service Operations
2.1 References
Section 6E1 Emission Control – V6 Engine in the MY 2003 VY and V2 Series Service Information, contains reference to
other MY 2003 VY and V2 Series Sections. Due to different components and maintenance procedures, the following
references must be substituted for the corresponding reference in Section 6E1 Emission Control – V6 Engine in the
MY 2003 VY and V2 Series Service Information.
Heated Oxygen Sensors (HO2S)
For service procedures of the heated oxygen sensors, refer to Section 6C1, 6.1 Oxygen Sensor.