Text preview for : en_4j2_1g.pdf part of Daewoo Nubira/Lacetti Also known as: Chevrolet Nubira / Lacetti, Chevrolet Optra Optra5, Suzuki Forenza Reno Covers the 1.4L, 1.6L and 1.8L engine. Year 2004



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SECTION : 1G

ENGINE EXHAUST
TABLE OF CONTENTS
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 1G­1 Fastener Tightening Specifications . . . . . . . . . . 1G­1 COMPONENT LOCATOR . . . . . . . . . . . . . . . . . . . . 1G­2 Exhaust System . . . . . . . . . . . . . . . . . . . . . . . . . . 1G­2 MAINTENANCE AND REPAIR . . . . . . . . . . . . . . . 1G­3 ON­VEHICLE SERVICE . . . . . . . . . . . . . . . . . . . . . 1G­3 Catalytic Converter . . . . . . . . . . . . . . . . . . . . . . . . 1G­3 Exhaust Front Pipe . . . . . . . . . . . . . . . . . . . . . . . . 1G­4 Muffler ­ Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1G­6 Muffler ­ Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1G­7 GENERAL DESCRIPTION AND SYSTEM OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exhaust System . . . . . . . . . . . . . . . . . . . . . . . . . . Muffler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Catalytic Converters . . . . . . . . . . . . . . . . . . . . . . . 1G­9 1G­9 1G­9 1G­9

SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
Application Catalytic Converter­to­Exhaust Manifold Nuts Exhaust Front Pipe­to­Catalytic Converter Nuts Exhaust Manifold Cover Bolts Exhaust Front Pip­to­Front Muffler Front Muffler­to­Rear Muffler Nuts Front Bracket­to­Cylinder Block Bolt Catalytic Converter­to­Underbody Shield Front Muffler­to­Underbody Shield Rear Muffler­to­Underbody Shield NSm 40 40 15 30 30 50 2.5 2.5 2.5 Lb­Ft 37 30 11 22 22 37 ­ ­ ­ Lb­In ­ ­ ­ ­ ­ ­ 22 22 22

1G ­ 2IENGINE EXHAUST

COMPONENT LOCATOR
EXHAUST SYSTEM

1. 2. 3. 4. 5. 6. 7.

Exhaust Rear Muffler Muffler Gasket Exhaust Front Muffler Muffler Gasket Exhaust Front Pipe (1.8D) Exhaust Front Pipe (1.6D) Catalytic Converter

8. 9. 10. 11. 12. 13.

Exhaust Pipe Front Gasket Exhaust Front Pipe Gasket Exhaust Manifold Catalytic Converter Protective Shield Front Muffler Protective Shield Rear Muffler Protective Shield

DAEWOO V­121 BL4

ENGINE EXHAUST 1G ­ 3

MAINTENANCE AND REPAIR
ON­VEHICLE SERVICE CATALYTIC CONVERTER
Removal Procedure
1. 2. 3. Disconnect the negative battery cable. Disconnect the oxygen sensor electrical connector. Remove the exhaust manifold cover with the bolts.

4. Remove the catalytic converter upper flange nuts. Important : The nuts and the stud may unscrew as a unit because of the high temperature associated with the exhast manifold, but they can be re­used as such

5. 6. 7. 8. 9.

Remove the exhaust front pipe mounting bracket bolt. Remove the nuts from the exhaust front pipe­to­ catalytic converter flange. Remove the catalytic converter and the gasket. Clean the sealing surfaces on the exhaust front pipe flange and the exhaust manifold. Check the exhaust front pipe and the exhaust manifold for holes, damage, open seams or other deterioration which could permit exhaust fumes to seep into the passenger compartment.

DAEWOO V­121 BL4

1G ­ 4IENGINE EXHAUST Installation Procedure
1. Install the catalytic converter and the gasket to the exhaust front pipe flange.

Tighten
Tighten the exhaust front pipe­to­catalytic converter nuts to 40 NSm (30 lb­ft). Tighten the exhaust front pipe­to­cylinder block bolt to 50 NSm (37 lb­ft).

2.

Install the catalytic converter to exhaust manifold nuts and the gasket.

Tighten
Tighten the catalytic converter to exhaust manifold nuts to 40 NSm (30 lb­ft).

3.

Install the exhaust manifold conver bolts.

Tighten
4. 5. Tighten the exhaust manifold cover bolts to 15 NSm (11 lb­ft). Connect the oxygen sensor electrical connector. Connect the negative battery cable.

EXHAUST FRONT PIPE
Removal Procedure
1. Remove the crossmember lower bracket with the bolts.

DAEWOO V­121 BL4

ENGINE EXHAUST 1G ­ 5
2. 3. 4. Disconnect the oxygen sensor connector. Remove the exhaust front pipe mounting bracket bolt. Remove the nuts from the exhaust front pipe­to­ catalytic converter flange.

5. 6. 7. 8.

Remove the nuts from the exhaust front pipe­to­ exhaust front muffler. Remove the exhaust front pipe and the gasket. Clean the sealing surfaces on the exhaust front muffler pipe flange and the exhaust front pipe. Check the exhaust front pipe for holes, damage, open seams or other deterioration which could permit exhaust fumes to seep into the passenger compartment.

Installation Procedure
1. 2. Install the exhaust front pipe and the gasket. Install the nuts from the exhaust front pipe­to­exhasut front muffler.

Tighten
Tighten the exhaust front pipe­to­exhaust front muffler nets to 30 NSm (22 lb­ft).

3. 4.

Install the nuts from the exhaust front pipe­to­catalytic converter flange. Install the exhaust front pipe mounting bracket bolt.

Tighten
Tighten the exhaust front pipe­to­catalytic converter nuts to 40 NSm (30 lb­ft). Tighten the exhaust front pipe­to­cylinder block bolt to 50 NSm (37 lb­ft). Connect the oxygen sensor connector.

5.

DAEWOO V­121 BL4

1G ­ 6IENGINE EXHAUST
6. Install the crossmember lower bracket bolts to 35 NSm (26 lb­ft).

MUFFLER ­ FRONT
Removal Procedure
1. 2. Remove the nuts and the gasket from the front muffler pipe to the exhaust front pipe flange. Disconnect the front muffler from the rubber hanger.

3. 4. 5.

Remove the nuts and the gasket from the rear muffler pipe flange. Remove the front muffler. Check the exhaust pipe and the front muffler for holes, damage, open seams, or other deterioration which could permit exhaust fumes to seep into the passenger compartment or the trunk.

Installation Procedure
1. 2. Connect the front muffler to the rubber hanger. Attach the front muffler and the gasket to the rear muffler using the nuts. Secure the front muffler to the rubber hanger.

Tighten
Tighten the front muffler­to­rear muffler nuts to 30 NSm (22 lb­ft).

DAEWOO V­121 BL4

ENGINE EXHAUST 1G ­ 7
3. 4. Loosely secure the front muffler assembly to the connecting pipe flange. Secure the front muffler assembly to the connecting pipe flange with the nuts.

Tighten
Tighten the front muffler­to­exhaust front pipe nuts to 30 NSm (22 lb­ft).

MUFFLER ­ REAR
Removal Procedure
1. Remove the nuts and the gasket from the rear muffler pipe flange­to­front muffler pipe flange.

2. 3. 4.

Detach the rear muffler assembly from the rubber hangers on the tail pipe end. Remove the rear muffler assembly. Check the rear muffler and the pipe for holes, damage, open seams, and other deterioration which could permit exhaust fumes to seep into the passenger compartment or the trunk.

Installation Procedure
1. Secure the rear muffler assembly to the rubber hangers on the tail pipe end.

DAEWOO V­121 BL4

1G ­ 8IENGINE EXHAUST
2. Secure the nuts and the gasket from the rear muffler pipe flange­to­front muffler pipe flange.

Tighten
Tighten the front muffler­to­rear muffler nuts to 30 NSm (22 lb­ft).

DAEWOO V­121 BL4

ENGINE EXHAUST 1G ­ 9

GENERAL DESCRIPTION AND SYSTEM OPERATION
EXHAUST SYSTEM
Notice : When you are inspecting or replacing the exhaust system components, make sure there is adequate clearance from all points on the underbody to avoid possible overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials. CAUTION : Check the complete exhaust system and the nearby body areas and the trunk lid for broken, damaged, missing, or mispositioned parts, open seams, holes, loose connections, or other deterioration which could permit hazardous exhaust fumes to seep into the trunk or the passenger compartment. Dust or water in the trunk may be an indication of a problem in one of these areas. Any defects should be corrected immediately.

MUFFLER
If holes, open seams or any deterioration is discovered upon inspection of the front muffler and pipe assembly, the complete assembly should be replaced. The same procedure is applicable to the rear muffler assembly. Heat shields in the front and the rear muffler assembly positions, as well as for the catalytic converter and the connecting pipe, protect the vehicle and the environment from high temperatures the exhaust system develops.

CATALYTIC CONVERTERS
Notice : The catalytic converter requires the use of unleaded fuel only, or damage to the catalyst will result. The catalytic converters are emission control devices added to the exhaust system to reduce pollutants from the exhaust pipes. The three­way catalyst has coatings which contain palladium, platinum and rhodium, which simultaneouly lower the levels of HC, CO and NOx.

DAEWOO V­121 BL4