GR / VA Subaru Catback


GR / VA Subaru Catback

WRX 2008 - 2021
WRX STi 2008 - 2021

Congratulations on your purchase of the COBB Tuning Subaru STI Catback. The following instructions will assist you through your installation process. Please read them first BEFORE beginning the install and familiarize yourself with the steps and tools needed. If you feel that you cannot properly perform this installation, we HIGHLY recommend you take the vehicle to a qualified and experienced automotive technician.

Part List

  • Straight Pipe
  • Y-Pipe
  • Driver's Side Muffler/Tips Section
  • Passenger's Side Muffler/Tips Section
  • 6x M10 x 35mm Bolts
  • 6x M10 Nuts
  • 3" Flange Gasket
  • 2x 2.5" Flange Gasket

Tools Needed

  • Ratchet
  • Sockets: 14mm, 12mm
  • Optional: Exhaust Hanger Removal Tool, Silicone Lubricant

Removal of Stock Catback

  1. Begin the removal process by loosening and removing the spring bolts holding the stock catback to the downpipe. Use a 14mm and 12mm to do so. NOTE: Keep this hardware, it will be used during the installation of the COBB Catback.

  2. Go ahead and take the donut gasket off of the end of the downpipe so that it is not damaged by potentially falling to the ground. 

  3. There are 5 exhaust hangers that need to be removed from grommets so that the stock catback can be uninstalled. Remove the 4 hangers in the back that support the two mufflers first and then remove the hanger that is supporting the center of the catback. It is recommended that two people are used for this job!


  4. Once the exhaust hangers are removed from the grommets, the catback should fall out of place. 

Installation of COBB STI/WRX Catback

  1. To install the COBB Catback, it is easiest to install on the car as an assembled piece rather than part by part. 

  2. Use the hardware provided to bolt the catback together. Be sure that you place a flange gasket between each flange! The 3" gasket connects the straight pipe to the Y-pipe and the two 2.5" gaskets are used to connect the Y-pipe to the two muffler sections. Use a 14mm wrench or socket to tighten all of the hardware, and make sure that the flanges line up when you are tightening.

  3. Install the COBB Catback by first placing the middle hanger in the grommet.

  4. Now place the remaining 4 hangers near the mufflers in the stock grommets. (Pictures only show driver's side muffler section. Passenger's side is mirrored.)

  5. With the catback being supported by the hangers, you can now place the donut gasket onto the downpipe. Next use the spring bolts you saved from before to bolt the COBB catback to the downpipe.


  6. Examine the fitment of your exhaust and adjust the flanges where needed. 

  7. Double check to make sure that all of the nuts and bolts are nice and tight! Enjoy your new COBB Catback!


Subaru Installation Instructions 

Main Installation Instruction Repository for Subaru Parts


Link to Subaru Map Notes to see what map you should be on given the parts you've added

Error rendering macro 'excerpt-include' : You can only link to a page or blog post.