Daewoo NUBIRA, User Manual

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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).