TESTED: Ford Performance Cat-Back Exhaust and GT350 Valence

mustang gt exhaust offWith the clamps clear of the front catalytic pipe, we can now work on removing the rear of the exhaust.

mustang gt rear exhaust mountThe middle of the exhaust hangs on these rubber mounts. It is easier to unbolt the bracket and remove the bushing from the hanger when the exhaust is on the ground.

Mustang gt rear muffler bushingThe mufflers hang from these bushings at the rear of the frame rail.  Like the center mounts at the diff, it is easier to unbolt the bracket to remove the exhaust from the car.

2015 mustang gt rear exhaust removedWith the exhaust brackets removed, the entire exhaust assembly slides right off the car. This is a two-man job.

Stock 2016 Mustang GT exhaust on floorAs you can see, the entire factory exhaust is one massive, large, and heavy piece. Now that the exhaust is down, we can remove the brackets and install them on the new exhaust.

2015 Mustang gt valence removal screwsThe next step is to remove the original black valence via a bunch of 8mm body screws, plastic push-pins, and prying the many plastic clips from the body. The supplied installation manual recommends removing the rear bumper first to make this easier, but every time you remove the bumper, the clips become weaker and it can become a frustrating battle to keep the rear bumper attached to the quarter panel, in which case the only real fix is to replace all the brackets and rear bumper cover with new ones. In order to avoid this, and due to his extensive Mustang knowledge, Will from RareFab found it easier to remove the valence while keeping the bumper on the car.

2015 Mustang GT rear valence removedWith some time and patience, the black valence is removed. It would probably take more time to remove and re-install the rear bumper than it did to reach and unlatch some of the more difficult center valence clips.

2015 Mustang gt cut off rear diffuserThe next step is to cut the one-piece body colored ‘diffuser’ from the rear bumper itself.  The ‘diffuser’ actually clips to the rear valence, which is then attached to the bumper. The only reason the diffuser is attached to the bumper is to keep it one piece for painting at the factory.

2015 Mustang GT rear diffuser cut offWith the diffuser cut off, we were ready to install the new Ford Performance diffuser and valence.

Ford Performance Exhaust boxNow that our exhaust and valence is removed, we can turn our attention to opening the boxes from Ford Performance. As a car guy, opening boxes of car parts always feels like Christmas.


  1. Great sounding cat back. But how much louder is the sport from Ford Performance? Also is the tone deeper on the Ford Performance than on the Borla?

      1. I have a 2017 GT PP and I have the Ford Performance power pack level 2 installed by My local dealer. Would I benefit more from the touring or sport cat back?

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