Pontiac Fiero 1988 Service Manual page 712

EXHAUST SYSTEM 6F-1
SECTION 6F
EXHAUST S Y S T E M
C A U T I O N : E x h a u s t system
components
should
have
e n o u g h c l e a r a n c e from t h e u n d e r b o d y
to a v o i d o v e r h e a t i n g and p o s s i b l e damage t o t h e passenger compartment c a r p e t s .
CONTENTS
G e n e r a l D e s c r i p t i o n
6F-1
Exhaust Pipe 6F-1
Muffler 6F-1
Hanger 6F-1
Clamp . 6F-1
Catalytic Converter 6F-1
Exhaust System Spring Installation . . . . . . . . . . 6F-3
GENERAL DESCRIPTION
When inspecting or replacing 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.
Check complete exhaust system and nearby
body areas for broken, damaged, missing or
mispositioned parts, open seams, holes, loose connec-
tions, or other deterioration which could permit
exhaust fumes to seep into the passenger compart-
ment. Dust or water in the passenger compartment
may be an indication of a problem in one of these
areas. Any defects should be corrected immediately.
To help insure continued integrity, the exhaust system
pipe rearward of the catalytic converter must be
replaced whenever a new muffler is installed.
EXHAUST PIPE
The exhaust manifold to exhaust pipe connec-
tion is of the flex joint type, and requires a graphoil
seal.
MUFFLER
The muffler is a tri-flow design, located at the
rear of the vehicle, mounted transversely. The com-
plete exhaust system is a one piece design constructed
of stainless steel.
HANGER
Spring type hangers are used to support the
complete exhaust system.
The installation of exhaust system supports is
very important, as improperly installed supports can
cause annoying vibrations which are difficult to
diagnose.
CLAMP
When servicing a welded connection, it should
be cut and the new connection clamped when install-
ing replacement parts. Also, coat slip joints with
exhaust system sealer before assembling (Figure 1).
S L O T IN PIPE
- H
~*-^
m6
EXH. CROSSOVER TO EXH. PIPE
3/8 REMAINING JOINTS
EXHAUST SYSTEM U-BOLT CLAMPS
POSITION CLAMP AS SHOWN IN RELATION
TO SLOT TO PREVENT GAS LEAKS
520001-6F
Figure 1 Installation of Exhttist System Clamp
CATALYTIC C O N V E R T E R
The catalytic converter is an emission control
device added to the exhaust system to reduce pollut-
ants from the exhaust gas stream.
NOTICE:
THE CATALYTIC CONVERTER
REQUIRES THE USE OF UNLEADED FUEL
ONLY.
Periodic maintenance of the exhaust system is
not required, however, if the car is raised for other
service, it is advisable to check the general condition
of the catalytic converter, pipes and mufflers.
Three different converter designs are used in
combination with two different types of catalyst.
1. Converter Design:
• Dual Bed Monolith
• Single Bed Pellet
• Dual Bed Pellet