How to Install Corsa 3 in. Sport Cat-Back Exhaust w/ Polished Tips - Split Rear Exit (10-13 6.2L Sierra 1500) on your GMC Sierra

Please take time to read and understand these installation instructions.

CORSA recommends that installation of this system be performed by a qualified service center or professional muffler installer who has the necessary equipment, tools and experienced personnel. However, if you decide to perform this install, the use of a hoist and an additional person will be required.

CAUTION: Never work on a hot exhaust system. Allow time for the vehicle to cool. Always wear eye protection when working under a vehicle.

Please confirm that all parts are present before beginning the factory exhaust system removal and CORSA exhaust system installation.

1) Open cover next to rear license plate and use vehicle key to remove lock and access to spare tire removal shaft (See Fig. A) 

2) Use the spare tire removal kit from your vehicle and place the square end into the spare tire removal shaft then turn the wrench counter clock wise to lower the spare tire. 

3) Mark tailpipe 3.25” rearward of the 2nd hanger after main tunnel muffler. Place a chain style cutter around the tailpipe at mark and cut the tailpipe at this location. (See Fig. B & C) A reciprocating saw may also be used. 

4) Remove the rearmost hanger from the grommet using grommet pullers or similar device. (See Fig. D) 

5) Remove the tailpipe section from the vehicle by lifting the tailpipe over the rear axle and backwards under the rear bumper. 

6) Use a 15mm socket and ratchet to remove the flange nuts at the flange connection of the headpipe. Then remove the hangers at the headpipe location and the hanger after the muffler. Remove the tunnel muffler section away from the vehicle. This completes the removal of the stock system. (See Fig’s E, F, G & H)

1) Locate the CORSA Head Pipe assembly and slide the flange studs into the factory flange. Use the nuts supplied with the CORSA hardware kit and evenly tighten down to 45 Ft-lbs. Insert the hanger in to the factory grommets. (See Fig’s J & K) Note: Using a soapy solution on the grommet hole will make the job easier. 

2) Slide a supplied 3” TORCA clamp over the inlet of the CORSA muffler. Make sure the drain hole is facing down. Slide the muffler onto the Head Pipe and pre-tighten the clamp. (See Fig’s L, M and N) 

-------------------- FOR DUAL UNDER THE BUMPER, SKIP TO STEP 3 ON PAGE 5. -------------------- 

3) Slide a supplied 3” TORCA clamp over the inlet of the CORSA Tailpipe. From the rear of the vehicle slide the pipe over the axle while holding the rear differential vent hose out of the way. Insert the pipe over the muffler exit and place the hangers into the factory grommets. (See Fig’s O, P & Q) 

Note: Using a soapy solution on the grommet hole will make the job easier.

DUAL UNDER THE BUMPER INSTRUCTIONS CONTINUED...

3) Slide a supplied 3” TORCA clamp over the inlet of the CORSA Dual “Y” Assembly and insert over the muffler exit and place the hangers into the factory grommets. Pre-tighten the clamp. (See Fig’s T, U, V & W) Note: Using a soapy solution on the grommet hole will make the job easier.

4) Slide a 2.5” TORCA clamp over the passenger side tailpipe assembly and place the pipe onto the upper end of the Dual “Y” Assembly and insert the hanger into the factory grommet. Pre-tighten the clamp at this time. (See Fig’s X, Y, Z, & AA) 

Note: Using a soapy solution on the grommet hole will make the job easier.

5) Slide a 2.5” TORCA clamp over the “Driver over the axle Pipe” and place the pipe onto the lower end of the Dual “Y” Assembly. Leave the pipe loose at this time for adjustment when placing the driver side tailpipe onto the over the axle pipe. (See Fig’s BB, CC, & DD) 

6) Locate Driver Side tail pipe hanger assembly (“U” shaped Wire Loop & Plate) and hardware (threaded Mounting Plate, bolt and washers) (See Fig. EE). On the driver side of the vehicle, position the threaded rectangular-shaped mounting plate on top of the frame rail over the hole located furthest forward from the rear of the frame rail. (See Fig. FF & GG) 

7) Insert the supplied 5/16”-18 bolt through the tail pipe Wire Loop & Plate hanger and thread it into the threaded Mounting Plate on top of the frame. Note: Position the driver side hanger so that it faces toward the spare tire (See Fig. HH) 

8) Slide a 2.5” TORCA clamp over the inlet of the drivers side tailpipe and install tail pipe onto the over the axle pipe (See Fig’s II, JJ & KK). Insert tail pipe hanger into provided rubber grommet and pre-tighten clamp at this time. Note: Using a soapy solution on the grommet hole will make the job easier. 

9) Locate exhaust tip assemblies and slide 2.5” TORCA clamp over expanded end of tip assembly. With the bolt and nut facing up, snug fit the clamps on each tip assembly. Do not tighten at this time. (See Fig’s LL & MM)

NOTE: Failure to follow these instructions and maintain the recommended clearances to the above listed parts could impact the long term performance of said parts. Please contact the CORSA Performance Customer Service Department (800-486-0999) if you have any questions related to the above information.

NOTE: During cold weather start-ups, you may experience an exhaust sound that is deeper and louder in tone than usual. This is temporary and will diminish to normal levels once your engine has reached its normal operating temperature. 

NOTE: Immediately following the installation of your CORSA exhaust system, you may experience a trace of smoke after initial start-up. DO NOT be alarmed. The smoke is caused by the burning of a small amount of forming oil residue used in the manufacturing process.