Special discount price: enter JUNE at checkout for 9% off. *
close promo banner icon

cat-back

Flowmaster - American Thunder Cat Back Exhaust System (817750)

rating-star review rating-star review 1rating-star review 2rating-star review 3rating-star review 4

$799.95

$888.95

You save: $89.00 (10%) off MSRP

stock messaging Out of StockOut of Stock
Order now to be added to the priority list
Check to see if this fits your vehicle

This part fits

  1. 2018 Ford Mustang EcoBoost 2.3L L4 cid:140 cc:2300
  2. 2018 Ford Mustang EcoBoost Premium 2.3L L4 cid:140 cc:2300
  3. 2016 Ford Mustang EcoBoost 2.3L L4 cid:140 cc:2300
  4. 2016 Ford Mustang EcoBoost Premium 2.3L L4 cid:140 cc:2300
  5. 2015 Ford Mustang EcoBoost 2.3L L4 cid:140 cc:2300
  6. 2015 Ford Mustang EcoBoost Premium 2.3L L4 cid:140 cc:2300
Authorized Dealer

About this product

Part #: 817750

Flowmaster's American Thunder Cat-back exhaust system for the 2015-2018 Ford Mustang is perfect for the person looking for an aggressive exterior sound level while maintaining a moderate interior sound with all of the performance benefits that you would expect from Flowmaster. This bolt on 409S stainless steel system for the 2.3L EcoBoost engine features 2.50in mandrel bent tubing that splits into dual 2.25in pipes for maximum performance and then runs into Outlaw Series mufflers. The system is finished off with dual 4.00in stainless steel tips that exit within the rear bumper valence. The exhaust system is covered by Flowmaster's Lifetime Limited Warranty. Designed for an easy fit, this system includes all necessary parts and hardware for installation. Note: This system fits hardtops and convertibles.

More Details

Catalytic Converter IncludedNo
ColorBlack
Exhaust TypeDual
Exit PositionDual Rear
Exit StyleStraight
Heat Shield AttachedNo
Inlet Diameter3.000 in.
MaterialStainless Steel
Mount TypeFlanged
Muffler Part NumberKit Only
Muffler SeriesOutlaw
Muffler TypeWelded Baffle
Outlet Diameter3.000 in.
Outlet Outside Diameter2.250 in.
ShapeOval
Single or DualDual
Sound LevelModerate/Aggressive
System TypeCat Back
Tail Pipe Diameter2.250 in.
Tail Pipe Diameter3.000 in.
Tip CutAngle
Tip Diameter4.000 in.
Tip FinishPolished
Tip MaterialStainless Steel
Tip Quantity2
Tip ShapeRound
Tip TypeDouble Wall
TitleFlowmaster 817750 Cat-back System - 409S- DOR - American Thunder Kit - Mod/Agg Sound
Tubing Diameter3.000 in.
Tubing MaterialStainless Steel
Additional Documents
  1. Certificate of Originpdf
  2. Installation Instructionspdf
  3. Warrantypdf

See what our community says about flowmaster products

product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
Came on car when purchased
Is this your first time buying from this brand? Did you consider other brands?
No. I had it on another mustang and wasn't a fan
Was it easy to install? Any installation tips that will help others?
Installed in driveway. Good fit, no issues
Once you've had a chance to use the product, did it meet your expectations?
Not a fan of the sound of flowmeter mufflers
View on Jacob 's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
It’s definitely louder but not too loud to where it’s annoying driving around
Is this your first time buying from this brand? Did you consider other brands?
Yes but flowmaster had the best sounding in my opinion and was all metal
Was it easy to install? Any installation tips that will help others?
They cut out the old one and put in the new in a few minutes
View on Ryan's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
sound and build quality
Is this your first time buying from this brand? Did you consider other brands?
no
Was it easy to install? Any installation tips that will help others?
yes, pretty straight forward install. make sure there is clearance in height (preferably have it on a lift) for the muffler section to the tail pipe as there is considerable bend to manipulate in order to remove it. Also, just unbolt the hanger vs pilling off the gromet, seemed much easier to do.
Once you've had a chance to use the product, did it meet your expectations?
yes.
Any additional comments?
gauging sounds both in and outside of cab. with the headers, no resonator, and an overall diameter increase to a single 3 1/2" (4" tail), even with the 50 series HD muffler, it is surprisingly alot louder.
View on Adm's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
It came installed on the car when I purchased it.
Is this your first time buying from this brand? Did you consider other brands?
First time with this brand. I would consider going to Magnaflow or Borla again, although the Flowmasters do sound amazing, they are a bit loud for normal use.
Was it easy to install? Any installation tips that will help others?
Came installed on the car, but the fit is good.
Once you've had a chance to use the product, did it meet your expectations?
These make the car sound very aggressive, you can hear the car coming from the other side of my small town. So they sound bad ass...but can be annoying for your neighbours and police.
View on Brett's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
Previous owner installed it.
Is this your first time buying from this brand? Did you consider other brands?
Yes but it looks and sounds awesome!
Once you've had a chance to use the product, did it meet your expectations?
Sounds amazing for a v6
View on Nate's build

TOP RATED Flowmaster Exhaust

  • Flowmaster - FlowFX Cat-Back Exhaust System  photo
    MFR# 717871Flowmaster - FlowFX Cat-Back Exhaust System
    $629.95$699.95
    Save $70.00 (10%) off MSRP
  • Flowmaster - FlowFX Cat-Back Exhaust System  photo
    MFR# 717880Flowmaster - FlowFX Cat-Back Exhaust System
    $249.95$277.95
    Save $28.00 (10%) off MSRP
  • Flowmaster - FlowFX Cat-Back Exhaust System  photo
    MFR# 717887Flowmaster - FlowFX Cat-Back Exhaust System
    $459.95$510.54
    Save $50.59 (10%) off MSRP
  • California prop 65 warningWARNING: Cancer and Reproductive Harm www.p65warnings.cs.gov

    *Some manufacturer restrictions apply.

    About Flowmaster

    Manufacturer of performance exhaust systems, mufflers, cold air intakes, turbo boost modules, catalytic converters, race mufflers, headers and numerous exhaust accessories for late model cars, trucks, off-road, Jeeps, SUV’s, classic muscle cars, powersports vehicles and more. Flowmaster® gives you lots of exhaust choices with 12 designs of chambered mufflers, 3 styles of our exclusive “laminar-flow” mufflers and a new line of FlowFX “straight-through” performance mufflers, along with 5 sound categories of exhaust systems, giving you the customer, the power to custom tailor the sound of your vehicle whether you prefer mild, moderate or aggressive tones and sound levels.

    Benefits of adding this mod

    An upgraded exhaust system is one of the easiest modifications that offers an immediate, noticeable performance improvement. Whether you’re cruising an M3 or modding a diesel truck, an upgraded exhaust will open up the restrictive factory system, allowing your engine to breathe better and deliver peak power! From lighter weight exhaust headers to improved cat-back systems, to better sounding mufflers, modifying your exhaust setup is a great place to express the character of your ride in a unique and cost effective way. Whatever you’re looking for in a modified exhaust system, we can provide the absolute best systems to make your vision a reality.

    shipping-worldwide-jpg

    we ship worldwide!

    Based in California with 3 warehouses across the country, we’re sending out shipments everyday of the week, even Saturdays. Because your next mod shouldn’t have to wait.

    + FREE GROUND SHIPPING ON U.S. ORDERS OVER $99
    International shipping icon
    Have a question? Ask an Expert!

    Finding the best parts can be tricky

    - but not to worry! Our team of experienced American Muscle, JDM, Euro, and off-road tuners are ready to answer your questions (as long as we’re not in the garage wrenching on our own builds).

    chat-iconLive Chat
    Ask our expert tuners anything!
    call_iconCall Us
    1 (800) 959-4304
    featured vehicle testimonial imagequote icon

    Wheelwell wants to be the new online hub for car parts and accessories.

    author testimonial image
    featured vehicle testimonial imagequote icon

    Wheelwell helps you organize all your stuff for your car, I’ve loaded all my cars on Wheelwell and you can see all the parts I’ve put in them and that may help you make a decision with your own build.

    author testimonial image

    Matt Farah

    Smoking Tire / The Drive

    featured vehicle testimonial imagequote icon

    Thank you for all the help, really. You guys are awesome. This is all great info and I really appreciate everything you have done to help me with my build.

    James M.

    Ford Focus ST

    featured vehicle testimonial imagequote icon

    Your customer service is wonderful. Thank you for taking care of this. My review will express all. Thank you!

    Wallace R

    Chevrolet Silverado 1500