Daewoo Nubira. Manual - part 144

ENGINE EXHAUST  1G – 11

DAEWOO V–121 BL4

4.  Place the rear muffler pipe into the front muffler

pipe.

5.  Secure the rear muffler pipe to the front muffler

pipe with the holding clamp, the washer, and the
nut.

Tighten

Tighten the front muffler pipe–to–rear muffler pipe
holding clamp nut to 70 N

S

m (52 lb–ft).

1G – 12

I

ENGINE EXHAUST

DAEWOO V–121 BL4

GENERAL DESCRIPTION
AND SYSTEM OPERATION

EXHAUST SYSTEM

Notice : When you are inspecting or replacing exhaust
system components, make sure there is adequate clear-
ance 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, the
nearby body areas, and the trunk lid for broken, dam-
aged, missing or mispositioned parts, open seams,
holes, loose connections or other deterioration
which could permit exhaust fumes to seep into the
trunk or 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 immedi-
ately.

MUFFLER

Aside from the exhaust manifold connection and the rear
muffler–to–front muffler joint, the exhaust system uses a
flange and seal joint design. The exhaust manifold– to–ex-
haust pipe connection is of the flex joint type.If holes, open

seams or any deterioration is discovered upon inspection
of the front muffler and pipe assembly, the complete as-
sembly should be replaced. The same procedure is appli-
cable to the rear muffler assembly.

Heat shields in the front and the rear muffler assembly
positions as well as in the catalytic converter, protect the
vehicle and the environment from high temperatures de-
veloped from the exhaust system.

CATALYTIC CONVERTERS

Notice : When jacking or lifting the vehicle from the body
side rails, be certain the lift pads do not contact the catalyt-
ic converter, as this could damage the catalytic converter.

Notice : The catalytic converter requires the use of un-
leaded fuel only, or damage to the catalyst will result.

The catalytic converter is an emission control device add-
ed to the exhaust system to reduce pollutants escaping
from the exhaust pipes.

The oxidation catalyst is coated with a catalytic material
containing platinum and palladium, which reduces levels
of hydrocarbon (HC) and carbon monoxide (CO) from the
exhaust gas. The three–way catalyst has coatings which
contain platinum and rhodium, which additionally lower the
levels of oxides of nitrogen (NOx).

1C – 12

I

DOHC ENGINE MECHANICAL

DAEWOO V–121 BL4

MAINTENANCE AND REPAIR

ON–VEHICLE SERVICE

VALVE COVER

Removal Procedure

1.  Disconnect the negative battery cable.
2.  Disconnect the breather tube from the valve cover.
3.  Disconnect the camshaft position sensor.

4.  Disconnect all of the necessary vacuum lines.
5.  Remove the spark plug cover bolts.
6.  Remove the spark plug cover.
7.  Disconnect the ignition wires from the spark plugs.
8.  Remove the valve cover bolts.
9.  Remove the valve cover washers.

10.  Remove the valve cover.
11.  Remove the valve cover gasket from the valve cov-

er.

DOHC ENGINE MECHANICAL  1C – 13

DAEWOO V–121 BL4

Installation Procedure

1.  Apply a small amount of gasket sealant to the cor-

ners of the front camshaft caps and the top of the
rear valve cover–to–cylinder head seal.

2.  Install the new valve cover gasket to the valve cov-

er.

3.  Install the valve cover.
4.  Install the valve cover washers.
5.  Install the valve cover bolts.

Tighten

Tighten the valve cover bolts to 8 N

S

m (71 lb–in).

6.  Connect the camshaft position sensor.

7.  Connect the ignition wires to the spark plugs.
8.  Install the spark plug cover.
9.  Install the spark plug cover bolts.

Tighten

Tighten the spark plug cover bolts to 3 N

S

m (27 lb–in).

10.  Connect all of the necessary vacuum lines.
11.  Connect the breather tube to the valve cover.
12.  Connect the negative battery cable.