The exhaust system components and configurations described
herein are based on Mazda's original designs. Since many aftermarket parts
deviate somewhat from original factory parts, your exhaust system may
vary.
Safety Precautions
For a number of different reasons, exhaust system work can be
among the most dangerous types of work you can do on your car.
Alwaysobserve the following precautions:
Support the car extra securely. Not only will you often be working
directly under it, but you'll frequently be using a lot of force--such as
heavy hammer blows, to dislodge rusted parts. This can cause a car that's
improperly supported to shift and possibly fall.
Wear goggles. Exhaust system parts are always rusty. Metal chips can be
dislodged, even when you're only turning rusted bolts. Attempting to pry pipes
apart with a chisel makes chips fly even more frequently.
If you're using a cutting torch, keep it at a great distance from both the
fuel tank and fuel lines. Stop what you're doing and feel the temperature of
fuel bearing pipes and the tank frequently. Even slight heat can expand or
vaporize the fuel, resulting in accumulated vapor or even a liquid leak near
your torch.
Watch where your hammer blows fall. You could easily tap a brake or fuel
line when you hit an exhaust system part with a glancing blow. Inspect all
lines and hoses in the area where you've been working before driving the car.
Special Tools
A number of special exhaust system tools can be rented from auto
supply houses or local stores that rent special equipment. A common one is a
tail pipe expander, designed to enable you to join pipes of identical diameter.
It may also be quite helpful to use solvents designed to loosen
rusted bolts or flanges. Soaking rusted parts the night before you do the job
can speed the work of freeing rusted parts considerably. Remember that these
solvents are often flammable. Apply them only after the parts are cool.
Catalytic Converter-Exhaust Manifold Mounted
REMOVAL & INSTALLATION
GLC
Remove the clamp supporting the pipe running from the exhaust mounted
converter to the front of the rear converter. Remove the nuts and the springs
which fasten the rear of this pipe to the front of the rear converter.
Remove the three nuts and washers fastening this pipe to the bottom of the
exhaust manifold mounted converter. Disconnect the secondary air line where it
passes into the top of this pipe.
Pull the pipe down and off the exhaust manifold mounted converter, then
forward and off the rear converter. Remove both gaskets.
Remove the nuts from the upper side of the flange on the exhaust manifold.
Then, pull the converter downward and off the exhaust manifold. Remove the
gasket.
Clean all flanges, then install a new exhaust manifold mounted converter
in reverse order, using new gaskets. Work the pipe connecting the two
converters onto the studs of the rear converter before connecting it with the
exhaust manifold mounted studs.
Catalytic Converter-Exhaust System Mounted
REMOVAL & INSTALLATION
GLC and 323
Remove the attaching nuts and washers/springs from the exhaust manifold or
exhaust manifold mounted converter studs. Disconnect the secondary air line
from the pipe connecting the two converters on the GLC. Remove the nuts and
washers from the studs or bolts on the front of the rear converter. On the
323, remove the bolts from the front of the front converter.
Pull the pipe downward and off the manifold mounted converter or manifold.
Then, pull it off the exhaust system converter. Remove all gaskets.
On the GLC, disconnect the secondary air line where it runs into the
converter. On both models, remove the studs and nuts connecting the main
exhaust system mounted converter to the front of the exhaust pipe. Pull the
unit forward and off the studs. Unbolt and remove the upper and lower heat
shields on the GLC. Remove the gasket.
Clean all flanges and install in reverse order, using new gaskets.
626/MX-6
The catalytic converter is integral with a pipe and the resonator, as well
as the pipe linking the resonator to the exhaust pipe and muffler. First,
support this assembly in front of the resonator.
Remove the nuts and springs holding the studs in the forward end of the
catalytic converter to the front pipe flange. Then, remove the nuts from the
forward ends of the bolts attaching the assembly to the center pipe and
muffler. Pull the bolts out to the rear.
On some vehicles, the catalytic converter is covered by
a heat shield-1984 626 shown
Remove the rubber support donuts at the forward hangers and at the
resonator. Then, lower the assembly at the rear and, when the rear is clear of
the flange behind, slide the converter studs out of the flange in the front
pipe. Remove the gaskets at both ends, as well as the ring type seal located
in the rear of the front pipe.
Clean all flanges and install in reverse order, using new gaskets and
seals.
The muffler (or main silencer) is located at the rear
of the exhaust system-1984 626 shown
Exploded view of the 1979-85 RX-7 exhaust
system
Muffler
REMOVAL & INSTALLATION
GLC
The GLC muffler assembly is attached at the front via a flange,
and at the rear via a clamped pipe connection.
Raise and safely support the front end on jackstands.
Unbolt the clamp at the rear, then slide it forward and away from the
connection.
Remove the nuts from the rear side of the flange at the front.
Support the assembly, then pull the bolts forward and out of the flange at
the front.
Remove the donut type hangers at the front and pull the rear hangers off
the support prongs.
Turn the assembly back and forth, then pull the rear pipe out of the
connector for the rear pipe and remove it.
Unbolt the halves of the heat shield from the front pipe and install it
onto the new assembly.
Remove the gasket from the flange at the front and replace it during
reassembly.
Installation is the reverse of removal. Make sure that all parts have
sufficient clearance from underbody members, beforetightening the clamps.
323
Raise and safely support the front end on jackstands.
Remove the nuts from the flange connecting the resonator rear pipe and
muffler inlet pipe.
Exploded view of the 323 exhaust system (non-turbo
shown)
Pull the bolts out at the front.
Disconnect the hangers from the prongs at the front and rear of the
muffler, and at the rear of the tail pipe, then remove the assembly. On the
Hatchback only, unclamp and remove the tail pipe, and install it on the new
assembly.
Installation is the reverse of removal. Make sure that all parts have
sufficient clearance from underbody members, beforetightening the clamps.
626/MX-6 and 929
The muffler or main silencer assembly is flanged at the front. The
muffler configuration is the same for both 626/MX-6 turbo and non-turbo models.
Raise and safely support the rear end on jackstands.
Exploded view of the 1983-89 626 exhaust system
(non-turbo shown)
Remove the nuts and bolts connecting the muffler at the flange. Then, on
gasoline engine vehicles, unhook the hangers at the prongs and remove the
assembly. On diesel-equipped vehicles, unhook the donut type rubber connectors
at the front and outboard on the rear support.
Installation is the reverse of removal. If the rubber hangers are broken
or worn, replace them. Make sure that all parts have sufficient clearance from
underbody members, beforetightening the clamps.
RX-7
1979-85 models are equipped with only one muffler, as opposed to
the dual muffler system used on 1986-89 RX-7s (with turbo and non-turbo
engines).
Raise and safely support the rear end on jackstands.
Remove the lower protective cover from the pre-monolith converter and the
rear of the exhaust pipes.
Remove the main converter cover.
Disconnect the split air pipe from the muffler by removing the flange
nuts.
Unhook and remove the muffler bracket rubber pieces.
Lower the muffler from the vehicle.
On dual muffler systems, remove the remaining muffler in the same manner.
Installation is the reverse of removal. Use new gaskets during
installation. Make sure that all parts have sufficient clearance from
underbody members, beforetightening the clamps.
Dual muffler exhaust system for the 1986-89 RX-7 (turbo
shown; non-tubo similar)
