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Mishimoto Down Pipe - Off-Road (15-18 Ecoboost)

Market Price $512.99 You Save 17% ($85.49)
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  • Item 390290
  • MPN# MMDP-MUS4-15

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    Features, Video & Details

    • Mishimoto Off-Road Down Pipe
    • Increases of 74.8 RWHP and 116.3 RWTQ with a Tune
    • Aggressive Exhaust Note
    • Free Flowing 3" Diameter Mandrel-Bent Tubing
    • 304 Stainless Steel Construction
    • Additional O2 Bung - Ideal for Adding a Wideband Sensor
    • Includes 3" to 2.25" Step Down Adapter
    • Computer Tune is Required for Operation
    • Intended For Off-Road, Track Use Only
    • Compatible with Factory or Aftermarket Cat-Back Systems
    • Fits 2015-2018 2.3L EcoBoost Mustangs

    Review & Installation Video

    Review & Install Video

    Hey guys, Stephanie with here with this Mishimoto downpipe that's available for all 2015 and up EcoBoost Mustangs. The Mishimoto downpipe is going to be for the EcoBoost owners who are looking for a stainless steel downpipe to replace the restrictive factory downpipe. This is a catted downpipe that allows for a factory or factory-like catback setup. The whole point of an aftermarket downpipe is to relieve some of the restriction around the turbo, because from factory it's pretty constricting. Opening up some of the air flow from the turbo can give some nice performance improvements. Basically when it comes to the turbo, if you're looking for performance, you're pretty much going to want air flow as unrestricted as possible so the turbo can spool quickly. The faster the turbo can spool, the more gains that you'll see. Taking a closer look at this downpipe here, it's a full three inch 304 stainless steel mandrel bent pipe with an optional step down. To break that down some, stainless steel is always going to be nice for exhaust components. You won't have to worry about corrosion with the Mishimoto downpipe. The idea behind mandrel bending is to get smoother exhaust flow. Smoother exhaust flow means more power and better performance. The step down is optional, which is great. If you run the adaptor, it's going to reduce the three inch down to a two and a quarter inch which leaves the option of keeping a stock catback or running an aftermarket two and a quarter inch one. Or, you can pair the downpipe with a three inch catback now or even down the road some. That means you can pick up the downpipe for some performance gains without having to purchase a complete new catback while you're at it unless you want to. Then you have some room to grow and the ability to upgrade in stages. A three inch downpipe is definitely going to be larger than the factory downpipe, which means that you are upgrading here. You're going to notice a difference when you compare the factory downpipe to this one here. This particular downpipe has a high flow cat, but if you're looking to get around that cat, Mishimoto does offer a downpipe that comes noncatted which is going to cost a little less than the catted version here which is typical to see in all exhausts. If you pick up the uncatted version of this downpipe then it's going to be even less restrictive than the catted version. Like I said, this is a high flow cat which means that it is more free flowing than the factory cat is. Even though the main idea behind an aftermarket downpipe is to help give the turbo unhindered air flow, swapping out your factory downpipe is also going to give you more sound, too, especially if you're running the uncatted version. You'll hear a lot more turbo noise and get more of that turbo four cylinder sound. Also, be sure to keep in mind that a computer tune will be required to run either the catted or the off road version of this downpipe, so it is going to be necessary to tune for this downpipe. Even if you are going with the catted version of any downpipe, it's always recommended to run a tune, especially if you want to be able to realize the full power potential behind upgrading your downpipe. Another nice thing about this downpipe is that it actually has the 302 bungs. This gives you room for the two O2 sensors and then another spot for a wide band as well which is always going to be a good idea when you start playing around with custom tunes and additional boost. This is a two piece design that comes with a floating two bolt flange, a slip joint connector, and a V band flange. It doesn't get any nicer than a good old V band. If you take a look here, you'll see that Mishimoto designed the downpipe to put the flex pipe in more of a horizontal position instead of a vertical one like some other brands do. What I've noticed with the downpipe offerings across all brands, at least at this point in time, is that generally speaking the higher end players like Kooks and CPE share the same ideas Mishimoto does here, while the less expensive options like BBK have the flex pipe vertically positioned. This is just a little food for thought. Pair that with the knowledge of the two three and it's firing order. When we look at price, the catted Mishimoto downpipe is pretty much right in the middle of the pack. It costs between $500 and $550 which is less expensive than Kooks, Stainless Works and CPE, but a little bit higher price than BBK. The offroad version is about $100 less. There are more options as far as brands with offroad downpipes. Mishimoto is still right around the middle of the pack there, too. When it comes to the install, luckily this isn't a bad one. You're probably looking at a few hours to get everything done. I'm going to call it a one out of three wrenches on the scale. This is obviously going to be easier to do on a lift, but of course you can get the job done using a jack and stands if you don't have access to one. You won't need anything out of the ordinary, just a few sockets, wrenches and a short extension. You're going to be removing the front and rear O2s for the install and swapping them over to the new downpipe. I'd just unclip and leave them in the factory downpipe and switch them after you get the old pipe out. This way you won't be twisting wires and it'll make for a faster install. You're going to be reusing the gasket from the turbo outlet, so don't forget to make sure to grab the factory downpipe gasket before installing the new downpipe, since sometimes the gasket can stick to the turbo. The third bung comes plugged, so if you're going to use it just remove the plug and put in your wideband sensor. If you're not ready for this yet, then just make sure that the plug is tight before you install the pipe. It's going to be easier to install the pipe in sections starting with the first section with the O2 sensors. Then, move on to the second section and insert the adapter, if you're going to use it, and through your reband on. The only other thing I'd say is to line the new downpipe up first before tightening everything down, but that's about it. So, only a few bolts and about two hours time for the install. Overall, the Mishimoto downpipe is a three inch stainless steel downpipe that can work with either a three inch catback or it can step down to work with a two and a quarter inch catback. You have a choice between either catted or noncatted depending on what you're looking for. Not only is this going to increase performance, but it's also going to open up some sound on the EcoBoost as well. You can check this out more online for yourself and see what you think. I'm Stephanie, and for all things Mustang keep it right here at

    More Power And Performance. A Mishimoto 3" Performance Off-Road Down Pipe will release all the hidden horse power and torque your Turbocharged 2.3L EcoBoost Mustang has to offer. Mishitmoto has seen dyno proven power gains of 74.8 horse power and 116.3 foot pounds of torque at the rear wheels with a custom tune.

    More Aggressive Sound. A Mishimoto Down Pipe not only helps improve power and performance of your S550 EcoBoost Mustang, but it also adds a much more aggressive exhaust note when compared to the factory down pipe.

    Stainless Steel Construction. Manufactured from high quality 3" diameter 304 stainless steel tubing for superior strength and corrosion resistance, this Mishimoto Down Pipe features smooth mandrel bends throughout the entire piping to improve exhaust flow for more power and better performance.

    Three O2 Bungs Built-in. Mishimoto designed their Down Pipe with three O2 bungs to accommodate the two stock O2 sensors as well as to give you the ability to easily add a wideband sensor if so desired.

    Required Upgrade. For proper operation and maximum power potential this Down Pipe will require reprogramming the vehicles computer. AmericanMuscle recommends a Bama custom tune with a Mustang Handheld Tuner to reprogram the vehicles computer (ECU) for proper operation.

    3" to 2.25" Adaptor Included. This Mishimoto Down Pipe can be installed onto an aftermarket 3" catback as well as the factory or an aftermarket 2.25" catback exhaust with the use of the included 3" to 2.25" step-down adapter. This adapter allows you to upgrade your EcoBoost Mustang in stages saving you money.

    Application. This Mishimoto Off-Road Down Pipe is designed to fit both automatic and manual 2015-2018 EcoBoost Mustang models equipped with the turbocharged 2.3L in-line 4-cylinder engine.

    Technical Note: This Mishimoto product is intended for off road use, and is not legal for use in emission restrictive states.

    Fitment: 2015 2016 2017 2018 Details

    What's in the Box
    • (1) 2-Piece Downpipe
    • (1) 3.0" Slip Joint Clamp
    • (1) 3.0" V-Band Clamp
    • (1) 3.0" to 2.25" Exhaust Adapter
    Installation Info
    Tech Specs
    Down Pipe Specifications
    Piping Material: 304 Stainless Steel Piping Size: 3" (includes 2.25" step down adapter)
    Catalytic Converter: "No" - For off-road use only Type Cat-Back Required: Stock, 2.25" or 3" aftermarket 
    Tune Required  Yes Fitment: 2015-2017 EcoBoost
    Will it fit my Mustang?

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    3 Questions / 3 Answers

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    will this down pipe work with the mbrp street cat back exhaust system


    • The Mishimoto Down Pipe - Off-Road (15-17 Ecoboost) will work with any exhaust that is a 3" or a 2.25" piping.


    Helpful (1)

    Can this downpipe be tune with the Cobb accessport?


    • Cobb does not offer a "off-the-shelf" tune for this Mishimoto Down Pipe, however, it can be used when the Accessport is used for a Cobb ProTune.


    Helpful (0)

    will this still work if you don't run a tune.


    • The down-pipe will function without a tune however, the vehicle with run rough due to the decrease in back pressure and not having a catalytic converter. Additionally, without a tune, a over-boost condition would be plausible.


    Helpful (0)

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    Customer Reviews (4) Write a Review

    Overall Rating 4.5

    out of 5 stars

    Installation Time:Afternoon

    • Loudness / Volume 5 5
    • Exhaust Note 4 4
    • Fit & Finish 3.666667 3.7
    • Bang For Your Buck 4 4

    • 5/5

      Installation Time: Full Day

      December 20, 2017

      Turbo sound

      It is a really tough fit to the turbo because of the gasket. I combined my downpipe with a mbrp race cat back 3 in exahust and it sounds amazing. Vey good product.


      Year: 2016 Submodel: EcoBoost

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      December 28, 2016


      Believe it! Added this plus a 93 custom tune and it was awesome! Huge HP and TQ gains!


      Year: 2017 Submodel: EcoBoost

      Helpful (2)

    • 5/5

      August 20, 2016


      MISHIMOTO IS THE BEST. Life time warranty and it is a 3in and I went with a 3in Stainless MBRP All the way out the back with a Cobb Tuner. I also went with all Mishimoto after cooler and piping and Turbo Smart BOV and you talk about HORSEPOWER. Look out GT'S. Made my 4 banger a real sleeper. And I also went with a Turbo Smart 10 lb. wastegate!!!!!!!!!!


      Year: 2015 Submodel: Ecoboost

      Helpful (4)

    • 3/5

      Installation Time: Afternoon

      June 27, 2016

      very loud

      the flange was to big for the gasket. mad it fit though


      Year: 2015 Submodel: Ecoboost

      Helpful (1)

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