Flowmaster Outlaw Series User manual

409S Stainless Steel
Before you begin, please understand that the installation of this system requires significant
disassembly of the rear fascia.
1) Before you begin, please understand that the installation of this system
requires significant disassembly. The entire lower rear bumper fascia
(Blue portion in photo) must be removed. Because this is a painted body
panel, you may want to consider covering it with masking tape for the
disassembly/assembly process to prevent any scratches. Note: Do not
turn the vehicle ignition on anytime during the removal/assembly
process
2) Begin by removing the rear license plate. Next, along the bottom of the
bumper fascia there are several screws that secure the lower edges.
Remove all of these screws (save all fasteners for reassembly).
3) On outside ends of each side of the bumper fascia there are small, plastic
vertical grates that must be removed. These are held in place by small
clips. Use a small screwdriver to carefully pop these out. At the bottom,
where the red and black panels touch, they clip together. Use a small flat
blade screwdriver to carefully separate them.
Installation Instructions for:
SYSTEM #817754
2014-17 CHEVROLET CORVETTE
6.2L ENGINE · AXLE-BACK SYSTEM
NOT INTENDED FOR VEHICLES W/ DUAL MODE OPTION
PACKING LIST
Qty Description Part #
1 Left Muffler 15188S
1
Right Muffler 15189S
1
Parts kit PK837
1 Laser Cut Spacer HA1626
4 ¼-20x3/4 Button Head HW238
4 ¼-20 Hex Nut HW101
4 ¼ Split Lock Washer HW301

4) On each side of the bumper fascia there is a thin horizontal red reflector
that must be removed. It is held in place with clips. Use a small flat
blade screw driver to very carefully pop out these two reflectors. Once
the reflectors are removed, you will see two hex bolts that secure the
fascia to the bumper frame. Remove these two bolts along with two that
are located under where the license plate was mounted.
5) In the cavity just above the exhaust tips, there are two last hex bolts that
need to be removed. At this point the panel is ready to be removed.
We’d recommend that you have a helper for this part. The panel is
secured along the top edge with clips. Grasp the panel at one end
through the vertical slot and carefully pull it out. This will take a little
muscle and finesse but it should pop right off. Once it’s off, place it in a
safe area out of the way.
6) This is what things should look like now. Now you need to start working
under the car so either put the car on a hoist, or put the rear of the car
on jack stands or ramps. At the rear, between the two factory mufflers
you will find that they are connected by small brackets that are secured
with small hex bolts. Remove these so that the mufflers can be removed
separately.
7) Just forward of the rear sub-frame and axles you will find a clamp
connection on each of the pipes. Loosen the nut on each of these
clamps. Up at the top on each of the pipes that run over the axle, there
is an electrical butterfly actuator. Disconnect the electrical connectors.
8) Above the outer edge of each muffler there is a hanger bracket bolted to
the frame that supports the muffler. Remove the bolts that secure one
side. Once it’s off you should be able to wiggle the muffler assembly
loose from the front connection and then out from over the axle.
Repeat for the other side. Slip the hanger brackets off the original
mufflers and slip them on to the new mufflers.
9) With the original mufflers out of the vehicle, remove the butterfly
actuators that are mounted to the pipes just forward of the mufflers.
These are secured by three small hex head screws.

10) Using the three hex head screws removed in the step above install
the butterfly actuators onto the valves in the new Flowmaster muffler
assemblies. Tighten the three screws securely.
11) Once the actuators have been installed onto the muffler assemblies,
the system can be reinstalled on the vehicle. Position one muffler at a
time, up over the axle into the clamped connection. Re-use the
original bolts to secure the rear hanger bracket up to the frame.
12) Once both mufflers are in place and supported, there are small
brackets at the rear that will connect them together. Use the two
supplied button head bolts, nuts and washers to secure the two
mufflers together. Reconnect the electrical connectors to the actuators
on the new mufflers.
The remainder of the installation is basically the reverse of the steps in the removal process. Once the rear
fascia is back in place, you can go back and make any necessary adjustment to the alignment of the
mufflers/tips before securely tightening down the inlet clamps and rear button head bolts. Note: The GM
service manual recommends that an “ACTUATOR LEARN PROCEDURE” be done when any changes
are made to the exhaust system. In our experience this is not necessary. However, if you experience a
check engine light or any other issues, it may be necessary to visit a GM dealer and have them run this
procedure on the vehicle.
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