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Stainless Works Performance Downpipe - Off-Road (15-19 EcoBoost)

Market Price $648.13 You Save 12% ($74.56)
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  • Item 387448

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    Features, Video & Details

    • Stainless Works Off-Road Performance Down Pipe
    • Increases Rear Wheel Horsepower and Torque
    • 304 Stainless Steel Construction
    • Free Flowing 3" Diameter Mandrel-Bent Tubing (Steps Down to 2.25")
    • More Aggressive Sound Compared to Stock
    • Intended for Off-Road, Track Use Only
    • Designed and Manufactured in the USA
    • Is NOT CARB Certified
    • Fits 2015-2019 EcoBoost Mustangs w/ 2.25" Cat-Back Exhaust

    Review & Installation Video

    Review & Install Video

    Hey, guys. Stephanie with here with a Stainless Works Performance Downpipe that's available for all 2015 and up Ecoboost Mustangs. The Stainless Works Downpipe is going to be for the Ecoboost owners who are looking to upgrade that restrictive factory downpipe, but still keep a factory or factory like Catback setup. The factory setup around the turbo is pretty constricting so opening up some of that airflow from the turbo can provide some pretty handy performance improvements. Basically when it comes to the turbo, if you're looking for performance, you're pretty much gonna want airflow as unrestricted as possible so the turbo can spool quickly. And the faster the turbo can spool, the more gains you'll see. So like I hinted at earlier this downpipe comes either catted or non-catted and we have the catted version here today. Looking at it closer, the first thing is this is a full three inches all the way down to the step-down right here. The step-down is gonna reduce 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, and that's one of the nice things about this downpipe. 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 that is. And Stainless Works also has a full three inch option out there too if you want to go with a Stainless Works Catback. The three inch portion up here is larger than the factory downpipe, which is where the less restriction comes from. And if you pick up the uncatted version, that's gonna be even less restrictive. But even the catted version does have a high flow cat which is more free flowing than the factory cats are. This is also fully made with 304 stainless steel, which is nice for those Mustangs that see all different types of road conditions, and the pipe is manual bent as well, just to help with smoother air flow. When using the off-road version, you will definitely need a tune since you're deleting the cat. And if you're going with a catted version, you can run it without a tune, but keep in mind that you'll see the full power potential behind upgrading a downpipe when you're running these with a tune regardless of whether or not it's catted. So even though the main idea behind an aftermarket downpipe is to help give the turbo unhindered airflow, swapping out your factory downpipe is also going to give you more sound too, especially if you're running the uncatted version. This downpipe is right in the middle of the road when it comes to price if we compare it to the other options that are out there right now. It costs between $450 and $550 depending on if you go with the off-road or the catted version with the off-road version being less expensive. 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, and I'm going to call this 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 on 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 gonna be removing the front and rear O2s for the install, but I'd just make sure to unclip those before you remove or reinstall them so you aren't twisting the wires. And of course, don't forget to grab the factory downpipe gasket before installing the new downpipe since sometimes a gasket can stick to the turbo. The only other thing I'd say here is to align the new downpipe up first before tightening everything down, but that's about it. Only a few bolts and not a whole lot of time for the install. So wrapping things up here this is a three inch downpipe that steps down to work with a two and a quarter inch Catback. It comes either catted or non-catted depending on what you're looking for. And not only is this gonna 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 Horsepower And Torque. Add even more horsepower and torque to the rear wheels of your turbocharged EcoBoost Mustang by installing a Stainless Works 3" Performance Off-Road Down Pipe. A Stainless Works Off-Road Down Pipe eliminates the power robbing stock catalytic converter to release all the hidden power and performance your S550 Mustang has to offer.

    More Aggressive Sound. Stainless Works Performance Down Pipe not only helps increase power and performance, but it also adds a much more aggressive exhaust note to your S550 EcoBoost Mustang, when compared to the stock down pipe.

    Stainless Steel Construction. Manufactured in the USA from 3" diameter T304 stainless steel tubing for strength and superior corrosion resistance, this Stainless Works Off-Road Down Pipe is mandrel bent for superior airflow - so there are no kinks to rob you of power.

    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.

    Application. This Stainless Works 3" to 2.25" Performance Off-Road Down Pipe is specifically designed to fit the 2015-2019 EcoBoost Mustang with the stock exhaust or an aftermarket  2.25" catback system installed.

    Technical notes. Not legal for use on pollution controlled motor vehicles; intended for off road use only.

    Fitment: 2015 2016 2017 2018 2019 Details

    MPN# M15EDP

    CA Residents: WARNING: Cancer and Reproductive Harm -

    What's in the Box
    • (1) Off-Road Down Pipe
    Installation Info
    Tech Specs
    Down Pipe Specifications
    Piping Material: Stainless Steel Piping Size: 3" (steps down to 2.25")
    Catalytic Converter: "No" - For off-road use only Type Cat-Back Required: Stock or 2.25" aftermarket 
    - Fitment: 2015-2017 EcoBoost
    Will it fit my Mustang?

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    Questions & Answers (1)

    1 Top Rated Question

    Would this fit with a Borla ATAK Catback?

    • Yes, the Borla ATAK Cat-Back Exhaust (15-19 EcoBoost Fastback w/o Active Exhaust) - Item# 387468 ( will fit with this item.

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    Customer Reviews (2) Write a Review

    Overall Rating 5

    out of 5 stars

    Installation Time:Full Day

    Installation Cost:$100-$250

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

    • 5/5

      Installation Time: Less than 1 Hour

      July 30, 2018


      Quality is unmatched in my opinion especially for the price! Does have a very minor fitment issue just because of the larger diameter of the pipe but was fixed easily with 2 washers


      Year: 2018 Submodel: EcoBoost

      Helpful (9)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $100-$250

      November 12, 2015

      Amazing Loud sound!

      Wasn't happy with just the axle back on my Ecoboost. So, combined this Kooks Downpipe with a Y pipe, existing Flowmaster Outlaw axle back and a tune from Bama. The exhaust sounds AMAZING. You absolutely can't go wrong with this exhaust combination. People get curious as to what is under the hood, and get surprised when they hear that 2.3 L makes the sound. If you want to get noticed, go for the above exhaust combination. Will cost you a couple thousands, but definitely worth it. Still get 30 on highways, and 19-21 in town depending on how I throttle.


      Year: 2015 Submodel: Ecoboost Bloomington, IL

      Helpful (13)

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