How to Install Magnaflow MF Series Black Cat-Back Exhaust - Split Rear Exit on your Sierra

Warning: When working on, under, or around any vehicle exercise caution. Please allow the vehicle's exhaust system to cool before removal, as exhaust system temperatures may cause severe burns. If working without a lift, always consult vehicle manual for correct lifting specifications. Always wear safety glasses and ensure a safe work area. Serious injury or death could occur if safety measures are not followed.  

Note: MAGNAFLOW Performance dual exit truck systems are designed to fit stock-height vehicles with OEM hitches and spare wheel and tire combos. Vehicles with aftermarket components such as trailer hitches, larger spare wheel and tire, or ride height changes may require modification of the exhaust system for a proper fit and finish. 

Step 1: (Carefully read all instructions  before installation) Disconnect the vehicle's battery before removal of the OEM exhaust. This will allow the computer to reset itself with the new system, and prevent electrical accidents. To remove the OEM exhaust system, you will first need to cut the pipe behind the muffler before it goes over the axle. You can then disengage the welded hangers from the rubber insulators and remove the tailpipe. Unbolt the muffler inlet from the catalytic converter at the clamp junction. Do not damage or discard the OEM fasteners or rubber insulators, as they will be reused to mount the new system. Disengage the muffler hangers and remove it from the vehicle.

Step 2: Install the new intermediate pipe at the ball flare using the OEM fasteners. Leave all clamps and  fasteners loose for final adjustment of the complete system. Working rearward, install the muffler, extension pipes, and tailpipes using the supplied hardware as shown in the system diagram. A hanger bracket and mounting fasteners are supplied to hang the driver's side tailpipe from a pre-drilled hole in the frame as shown in Diagram 2. Adjustable tip assemblies are provided to fit a variety of aftermarket bumpers and rollpans. Once a final position is chosen for the tips, it is recommended to have them welded to the tailpipes. 

Step 3: With all components mounted loosely, adjust the system for overall aesthetics and clearance of frame & bodywork. (MAGNAFLOW recommends at least 1/2" of clearance between the exhaust system and any body panels to prevent heat-related body damage or fire.)      

Step 4: Once a final position has been chosen for the new system, evenly tighten all fasteners from front to rear. The supplied band clamps must be VERY tight to properly align the pipes and prevent leaks (Approximately 40ft-lbs). Inspect all fasteners after 25-50 miles of operation and retighten if necessary.