Pontiac FIREBIRD 1972 Service Manual page 1135

FUEL TANK AND EXHAUST SYSTEM
8- 15
SEDAN TAlL PlPE
FRAME
ON PlPE AGAINST
FORWARD END OF
ALIGN TAlL PlPE ON
A HORIZONTAL PLANE
$
TO THE GROUND.
REAR SPRING SEAT
VlEW E
TAlL PI
HORIZONTAL
VIEW A
1
VlEW B
VlEW F
(EXC. STA. WAG.)
VlEW D
(STATION WAGON)
STAYION
WAGON
(EXC. STA. WAG.)
TAlL PlPE
Fig. 8 - 1 6 E x h a u s t S y s t e m C l e a r a n c e R e q u i r e m e n t s (A S e r i e s 6-Cyl.)
In the single exhaust system, the crossover pipe passes
under the engine oil pan from left bank to right bank and
then connects to an intermediate exhaust pipe. The inter-
mediate exhaust pipe runs along the right side to a'tri-flow
muffler which is attached to the tailpipe.
The dual exhaust system consists of two one-piece exhaust
pipes, two tri-flow mufflers and two tailpipes. The dual
exhaust system is standard equipment on G Series, GTO
and G T options and optional on other models (except A
Series station wagon).
Check complete exhaust system and nearby body areas
and trunk lid for broken, damaged, missing or misposi-
tioned 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 immediately.
To help insure continued integrity, the exhaust system
pipe rearward of the muffler must be replaced whenever
a new muffler is installed.
Resonators are not used.
F & X SERIES
Exhaust extensions installed on the GTO and G T options
have dual (split) outlets rather than single and they exit
to the side behind the rear wheel (Fig. 8-20).
The exhaust system is supported by conventional rubber
strap type hangers and clamps attached to the frame and
they keep the exhaust system in proper alignment. The
installation of these supports is very important, as improp-
erly installed supports can cause annoying vibrations
which are difficult to diagnose. When inspecting or replac-
ing exhaust system components make sure there is at least
3/4" clearance from the floor pan to avoid possible over-
heating of the floor pan and possible damage to the pas-
senger compartment carpets.
6-CYLINDER ENGINE
The 6-cylinder engine exhaust system (Figs. 8-21, 8-22
and 8-23) has a single outlet exhaust manifold. A seal is
installed between the manifold and exhaust pipe connec-
tion. There is a steel extension sleeve that fits into the seal
inside diameter to provide support. The manifold is con-
nected by a one-piece exhaust pipe clamped to a tri-flow
muffler. The exhaust pipe and muffler are indexed
together by a key (tab) welded on the exhaust pipe and a
slot in the muffler inlet pipe. The muffler and tail pipe are
welded together. This connection is clamped instead of
welded when either the tail pipe or muffler are replaced.