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Roush Cat-Back Exhaust (15-17 GT Fastback)

Item 408120
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$1,174.99 (kit)

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      Video Review & Installation

      Hey, guys, Adam here with, today we're taking a closer look at, installing, and of course listening to the Roush Cat-Back Exhaust available for the '15 to '17 Mustang GT. As you just heard from our sound clips right off the bat guys, I'm giving this four out of five on our loudness meter. It is extremely aggressive, very loud and pretty raspy but it isn't too overwhelming like you'd get with a five out of five kit. This guy here has all top quality materials T-304 stainless steel throughout, mandrel bends to help with increased airflow. It does have a resonator delete with an integrated X-pipe which is gonna contribute to that sound giving you a nice loud raspy tone and it also has bullet-style mufflers that are a straight-through design for high flow and increased volume without having excessive drone. Now, this kit does have a little bit of drone at highway speeds but again, not excessive, not overwhelming. You could definitely have a conversation in the cabin and listen to music freely but I will say start to finish on the RPM band this guy is loud and it is aggressive.Now, because it has all those high-quality materials and it carries that really reputable Roush name, it does carry a price tag of right around 1100 bucks, not the highest price tag on the market but it isn't really an entry level kit either. It's for the guys who know they want that T-304 stainless with that integrated X-pipe. Now, 304 stainless is a great option for guys like us here located on the East Coast, we see a lot of road salt in those wintery weather months and if you're not having a garage queen of a car, then you definitely want an exhaust that's gonna hold up in the long haul, 304 does that trick. As far as install is concerned, it's gonna get two out of three wrenches on our difficulty meter here, no welding, no cutting of the factory system. It is a direct bolt-on but it is a little bit more involved. Now, the cat-back here is gonna go on in a couple of different pieces, X-pipe, mid-pipe and then finally your bullet-style mufflers and tips. Factory exhaust comes off all in one piece which should be pretty simple. It'll take you about two hours from start to finish with very simple hand tools. I'm gonna show you every step of the way, let's get to it.Tools used in this install include an impact gun, extension, 13 and 15-millimeter deep sockets, also recommended would it be a hanger removal tool, a mallet and WD-40 or something similar. First up here guys, grab a 15-millimeter deep socket, we're gonna loosen up but not completely remove the nuts on both of the band clamps here connecting your factory resonator to your headers. So, we're just gonna loosen these guys up.All right. Next step we're gonna be at our rear subframe right behind our diff. Now, you'll see these hangers connect to the subframe itself using two 13-millimeter bolts. Now, we don't have to remove the hangers from the isolators, we're actually just gonna unbolt the whole isolator bracket from the frame. So, grab a 13-millimeter socket, and I like to use an extension to go right over the sway bar and we're going to remove these. Now, from there, what I'm gonna do is just lift up on this and swing these guys down. There's a little locking tab here that just hooks in, we just wanna unhook that. So, you may have to lift up on the exhaust and then bring it down.All right, next step before we remove the whole exhaust to one piece, I recommend grabbing WD-40 or something similar with this needle here to just lubricate the hanger above your tips. This is gonna make removing it a whole lot easier. All right, do the same thing on the other side. Next step guys, we're gonna take our exhaust off all in one piece. Now, you may want a helping hand if you're using a lift like we are, if you're working on the ground, might be a little easier for you to do by yourself. I'd recommend having a mallet to knock these band clamps back a little bit, disconnect it from this side, swing it back toward the front of the vehicle and set it aside. Got it?All right. So, we got our factory exhaust off of our 2015 GT and it's on the ground here next to our Roush cat-back. I wanna take you through some of the similarities and differences between the two kits. Let's start at the front of the vehicle. Now, as you can see, our new Roush cat-back is a resonator delete replacing the factory resonator, which really slows down the airflow, is a lot more restrictive than an aftermarket pipe like this one. And overall is really not gonna give you the sound that you want, or at least not the volume. Your new kit has an X-pipe integrated into the system which is gonna tremendously help with airflow. That in combination with the mandrel bends is really gonna help reduce any airflow restriction and the X-pipe is known to give you a nice raspy, louder volume and more aggressive tone than its counterpart being an aftermarket H-pipe.Moving on from there, the entire kit here is a mandrel bent 304 stainless steel, highest quality materials you can get in the category which means it's gonna last a lot longer and have less chance corroding and rusting out unlike your factory exhaust here. Now, this is a good option to get if you're located like us here on the East Coast seeing a lot of road salt. 304 stainless steel is gonna hold up a lot better to the weather elements and the road salt which is known to corrode some of those exhaust pipes and the undercarriage of vehicles.So, moving right along here you'll see a big difference in size between our new bullet-style muffler from Roush and the big factory mufflers from Ford. Now, these mufflers do muffle a lot of that sound exactly like it sounds like but it's really restricting that airflow as well. So, upgrading that to the high flow straight-through muffler it's really gonna open things up, produce a lot more volume and a lot more aggression.Exiting out the rear here, the last thing we'll talk about is the 4-inch polished stainless steel, 304 stainless steel tips. Unlike the smaller three, three and a half-inch tips from the factory. These look a lot better, they're a lot more polished, a lot more attractive and they're gonna hold up a lot longer as well. Ours is starting to discolor, not necessarily rusting, but it is losing its flashiness. Not gonna be the case here with the 304 stainless from Roush. And finally, it's get the Roush name embedded on the top, so it does add a nice little piece of repping the brand name right out the rear end. Now, they do have this option with black tips if you're looking to get a little bit more stealth out of the rear, but the chrome does blend in with a lot of the exterior parts already on the Mustang. So, I think it does look pretty good, but the black option is there, it's all personal preference. Now, before we get to the install, we do have to transfer over our hanger brackets that we removed from the rear subframe. So, let's pop those guys off and transfer them over.All right. So, I'm gonna use a hanger removal tool, makes life a lot easier. If they are giving you some trouble here you can use WD-40 again, like we did up on the vehicle, let's see how these pop off. Just gonna put this guy around, give it a pinch and they'll slide right out. All right, same thing other side. All right, let's transfer them over. Now, when you're swapping these over you wanna make note of this tab here, the tab at the top you want facing the front of the vehicle. So, let's slide these on just like that and push them down until we install them. All right, tab facing the front, slide them on, bring it down. First step of the install, you're gonna need your factory band clamps off of that resonator portion of your factory cat-back. So, grab those guys, you're basically gonna line up the open hole and tab here to the little welded on stopping button, that's gonna pretty much align these. So, we're just gonna slide these guys on just like that all the way back.All right, next up is our X-pipe. Now, as you can see the outlet for the X-pipe going toward the rear, one of them veers off to the left a little bit. That's gonna be your passenger side. So, we're gonna install that guy just like this and slide them into those factory band clamps. All right. So, grab your 15 socket and we're gonna tighten these guys down. Next step, grab your passenger side pipe here, we're gonna start there, make sure you have a clamp over the end connected to your X-pipe and then we'll hang up this bracket on the subframe. We're gonna rotate our bracket up and hook this tab into that bracket up on the subframe. Align the pipe where you need it to be, rotate it horizontally, let's tighten down the clamp. All right. So, now we can take that clamp and tighten her down. Repeat the same thing on the other side.Next up, we're gonna do our muffler on our passenger side. Make sure you have a clamp over the inlet there. We're gonna slide the hanger into the isolator first and then connect our pipe. I'm gonna bring it up here, push this guy in, line up our pipe at the back and slide them in. Now, tighten down this clamp. Now it's a good idea when you tighten down this clamp beforehand to just push up the pipe and make sure it's aligned generally where you want, we can go back and make adjustments later if need be. All right, same thing on the other side. Start with our hanger, slide that guy into place, and then connect your pipe. All right, last step's pretty simple. Grab your tip, along with another clamp, slide that guy into place and tighten it down. All right, do the same thing on the other side. Once your tips are in place here guys, go back and make sure everything is aligned where you want it to be. Look at the tips inside of that rear valance to make sure they're centered. Tighten all your clamps down so there's no exhaust leaks and make sure nothing would rattle on the frame or anything else, then you're good to go.That's gonna wrap up my review and install for the Roush Cat-Back Exhaust fitting all '15 to '17 GTs. This is gonna be a great fit for you and your S550, you can get yours right here at

      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Loud and Aggressive Sound
      • Optimizes Air Flow and Reduces Backpressure
      • Straight-Through, High-Flow Mufflers
      • Integrated Mid-Pipe and X-Pipe for a Race-Inspired Growl
      • Made From Heavy-Duty 304 Stainless Steel
      • Mandrel-Bent Tubing
      • Smooth, Polished Steel Finish
      • Chrome-Flashed Stainless Steel Tips
      • Straightforward Installation
      • Fits All 2015-2017 Models of the Ford Mustang GT Fastback


      Aggressive, Race-Inspired Sound. Turn everybody’s heads not just with the impressive appearance of your Mustang GT Fastback, but also with a loud and aggressive roar delivered by this Roush Cat-Back Exhaust. With two high-flow mufflers, an integrated mid-pipe, and X pipe, you’ll get significant performance boosts and a race-inspired growl that will make your Mustang sound as powerful as it looks.

      Reduces Backpressure to Increase Horsepower. This cat-back exhaust system is engineered to optimize air flow in order to reduce backpressure and therefore increase horsepower and torque. The integrated mid-pipe and X-pipe further increases the performance gains. They work together to smooth out the exhaust flow, make the engine more efficient, and deliver a raspy exhaust sound. The X-pipe also helps deliver more power in terms of RPMs.

      Mandrel-Bent 304 Stainless Steel. Roush constructed this cat-back exhaust system out of 304 stainless steel to ensure maximum toughness, long-lasting durability, and a lightweight structure. Using 304 stainless steel also means that this exhaust kit has excellent corrosion and temperature resistance. Moreover, the pipes are mandrel-bent to achieve smooth and uniform curves, which result in a non-restrictive air flow that boosts your Mustang’s performance and sound output.

      Polished Surface Finish. For an attractive finish with a subtle shine, the main components of this cat-back exhaust kit have been surface-polished. This process enhances the corrosion resistance of the steel and at the same time removes any impurities that may have been left after the forming process. The tips, meanwhile, are chrome-flashed for a high-shine finish that resists wear-and-tear.

      No-Weld Installation. This exhaust assembly doesn’t require any welding or drilling prior to installation. All you need are basic hand tools and the enclosed mounting hardware. Following the instruction manual, you can complete installation in approximately 2 hours.

      Application. This Roush Cat-Back Exhaust kit can be installed on all 2015-2017 models of the Ford Mustang GT Fastback.

      Fitment: 2015 2016 2017 Details

      Roush 422092

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) X-Pipe
      • (2) Intermediate Pipes (Left and Right)
      • (2) High-Flow Mufflers
      • (2) Muffler Tips
      • (4) Tip-to-Muffler Clamps
      • (2) Pipe-to-Muffler Clamps
      • (4) Heat Shield Clamps
      • Installation Instructions

      Customer Reviews (26)

        Reviews of Roush Exhaust products have an average rating of 4.8 out of 5

          Questions & Answers

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