FLOWMASTER 717890 FlowFX Cat Back Exhaust System Installation Guide
- June 13, 2024
- FLOWMASTER
Table of Contents
FLOWMASTER 717890 FlowFX Cat Back Exhaust System
OVERVIEW
- Take a moment to read and understand these instructions before installing your Flowmaster performance system.
NOTE: Please inventory all parts now before continuing and if necessary, report any missing items to our tech line. This will avoid potentially stranding your vehicle un? l any missing replacement parts arrive.
ITM # PART # DESCRIPTION QTY.
1| 36078M| Inlet Pipe| 1
2| 36065M| Extension Pipe| 1
3| 72587-Z| FlowFX Muffler| 1
4| 86546M| Left Front Tailpipe| 1
5| 86547M| Right Front Tailpipe| 1
6| 86548M| Left Rear Tailpipe| 1
7| 86549M| Right Rear Tailpipe| 1
N/A| PK1042| Hardware Pack includes:| 1
8| MC350BS| 31⁄2″ Band Clamp| 2
9| MC250BS| 21⁄2″ Band Clamp| 4
10| HW503| 1⁄2″ Hanger Keeper| 3
REMOVE FACTORY EXHAUST SYSTEM
- Raise vehicle up on a hoist or rack to working height. If you don’t have access to a hoist or rack, support vehicle with jack stands.
WARNING
Avoid serious burns! Allow your vehicle time to cool completely before
touching any factory engine components.
To ease preparation and installation of your new kit:
-
Apply penetrating lubricant to mounts, bolts and clamps before you remove them.
-
Use stands as necessary to support parts as you detach them from your vehicle and again as you install new parts.
-
Remove bolts (x2) and disconnect driver side tailpipe from exhaust at fl ange connection.
- Remove bolt and mount securing driver side tailpipe then remove it from vehicle. Retain bolt and mount for later use.
-
Cut tailpipes just behind factory muffler.
-
Disassemble passenger side tailpipe wire hangers (x2) from isolators. Remove bolt and mount near outlet then remove assembly from vehicle. Retain bolt and mount for later use.
- Loosen factory clamp from catalytic converter connection to disconnect inlet pipe, disassemble wire hanger from isolator then remove muffl er assembly completely from vehicle.
- Release tab and remove factory clamp from pipe inlet. Retain factory clamp for later use.
INSTALL FLOWMASTER EXHAUST SYSTEM
Remove nuts from stock and Flowmaster clamps, apply anti -seize compound to
bolts and re-install nuts.
NOTE: The image in this step is intended for illustrative purposes only
and may or may not accurately refl ect components included in your kit.
- Place clamp (removed step 8) onto inlet pipe (1) then connect it to catalytic converter. Mount wire hanger into factory isolator and ghten clamp just enough to allow for adjustment.
NOTE: Complete this step only if your vehicle requires an extension pipe. Reference specifi catoons below to verify.
WHEEL BASE BODY STYLE BED LENGTH INLET ASSY:
148″| Crew Cab| 5.8′| Inlet Pipe only
157″| Crew Cab| 6.6′| Inlet+Extension
148″| Double Cab| 6.6′| Inlet Pipe only
- Place clamp (8) onto muffl er (3) inlet. Place (x2) clamps (9) onto muffl er outlets. Connect muffl er to inlet or extension pipe then ghten front clamp just enough to allow for adjustment.
- Route right front tailpipe (5) and le front tailpipe (4) over axle and connect them to muffl er outlets. Mount wire hangers into isolators then ghten clamps (x2) enough to allow for adjustment.
- Place clamp (9) and mount (removed step 6) onto right rear tailpipe (7) then connect it to right front tailpipe. Bolt mount onto frame then ghten clamp enough to allow for adjustment.
- Place clamp (9) and mount (removed step 4) onto letirear tailpipe (6) then connect it to left front tailpipe. Bolt mount onto frame then fighten clamp enough to allow for adjustment.
-
Adjust exhaust components for fi t; maintaining ” clearance and compensating for suspension, travel and vibration then ghten all clamps. Finally, fi t (x3) hanger keepers (10) onto each sideways hanger.
-
NOTE: If your exhaust system still needs alignment, adjust isolator mounts in step 14 and 15.
-
Recommended: Secure slip-fi t connections with a 1-inch tack weld then spray high-temp paint over each weld to prevent rust and premature corrosion.
-
Congratulations, the installation of your FLOWMASTER performance exhaust system is now complete!
Installation Diagram
717890 201921 CHEVROLET SILVERADO 1500 & GMC SIERRA 1500 6.2L ENGINE 2/4 wheel drive & all wheelbases
www.flowmastermufflers.com. Technical Support 866-464-6553.