--- product_id: 10585568 title: "Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System" price: "2705.74 DT" currency: TND in_stock: false reviews_count: 8 url: https://www.desertcart.tn/products/10585568-flowmaster-817637-13-18-ford-focus-st-amt-409s-exhaust store_origin: TN region: Tunisia --- # Stainless steel durability Dyno-tuned aggressive sound Bolt-on easy installation Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System **Price:** 2705.74 DT **Availability:** ❌ Out of Stock ## Summary > 🚗 Unleash your Focus ST’s roar with Flowmaster precision! ## Quick Answers - **What is this?** Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System - **How much does it cost?** 2705.74 DT with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/10585568-flowmaster-817637-13-18-ford-focus-st-amt-409s-exhaust) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Built to Last:** Crafted from mandrel-bent stainless steel tubing for superior corrosion resistance and longevity. - • **Performance Meets Style:** Polished oval stainless steel tips add a sleek, aggressive look to your ride’s rear profile. - • **Precision Engineered Fit:** Bolt-on design tailored specifically for 2013-2018 Ford Focus ST hatchbacks—no modifications needed. - • **Complete Installation Kit:** Includes all necessary hardware for a hassle-free upgrade—get on the road faster. - • **Powerful Sound, Perfected:** Experience moderate to aggressive exhaust notes tuned for maximum performance. ## Overview The Flowmaster 817637 American Thunder cat-back exhaust system is a direct-fit upgrade for 2013-2018 Ford Focus ST hatchbacks, featuring dyno-tuned mufflers and resonators for a moderate to aggressive sound. Constructed from durable 2.25-inch mandrel-bent stainless steel tubing with polished oval tips, it delivers enhanced performance and style while ensuring easy bolt-on installation with included hardware. ## Description Flowmaster's American Thunder cat-back exhaust system for the 2013-2018 Ford Focus ST hatchback is perfect for the person looking for moderate to aggressive sound levels with all of the performance benefits that you would expect from Flowmaster. This bolt on Dual Out Rear emissions legal system for the 2.0L L4 turbocharged engine features a specially tuned muffler and resonator, 2.25 inch mandrel bent stainless steel tubing, and 3.25 x 3.75 inch oval polished stainless steel tips. Designed for an easy fit, this system includes all necessary parts and hardware for installation. Review: Some like it loud - The fact that this is one of the least expensive catbacks available for the Focus ST is what initially drew me to it. I first considered the MBRP catback but it just it was just too quiet. It didn't sound much different than my OEM exhaust with a resonator delete. I also like the fact that you can hear the turbo through the exhaust which is a nice little added bonus that makes it sound even better. This exhaust is loud, one of the loudest non-straight pipe exhausts you can get for the ST. This is mainly due to the fact that is has a single chambered resonator rather than a full-on muffler (basically a steel box with a hole on each end). The end result however is not a nasty, straight-pipe sounding exhaust. It is civil at low rpm's and has a nice deep tone for a 4-cylinder but on the top end once the turbo spools up it will wake the neighbors. Cons: No real cons for me. Interior drone doesn't seem to be much of a problem for me although other people have complained about drone. The interior sound level is not that bad at all and I don't notice much more drone than my stock exhaust with resonator delete. Quality/Install: The system is well designed and feels high quality although some have complained about the exhaust tip bolts being chintzy they seem average to me, so maybe they are using better quality bolts now. I had it installed at an exhaust shop so I can't comment on ease of installation too much aside from reading directions and watching install videos. It appears easy to install but I had a shop do it because I had issues with my jack/stands when I went to do the install myself and just opted to have it installed rather than wait another week.. Price: This exhaust seems overpriced for what it is honestly. It is a single chamber resonator which alone would cost maybe $75 and then about 8 feet of pipe with 2 tips. A good exhaust shop could probably fabricate a similar catback for a fraction of the cost, and the shop I took it to told me they could have gotten me the same system for $430 so SHOP AROUND! You will probably find it cheaper. Review: Sounds mint i love it. Alittle more drone than i was hoping ... - Sounds mint i love it. Alittle more drone than i was hoping for. Couldnt for the life of me get the tips to sit even so there alittle lop sided( didnt use a lift. Would have been easier) but i would highly recommend this and would buy again! ## Features - Great Performance Sound - Dyno Tuned For Maximum Performance - Stainless Steel Construction - Moderate to aggressive sound - Easy Installation ## Technical Specifications | Specification | Value | |---------------|-------| | Manufacturer | Flowmaster | | Brand | Flowmaster | | Model | 817637 | | Item Weight | 48 pounds | | Item model number | 817637 | | Is Discontinued By Manufacturer | No | | Exterior | Painted | | Manufacturer Part Number | 817637 | | OEM Part Number | 817637 | ## Images ![Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System - Image 1](https://m.media-amazon.com/images/I/41scoNkyWIL.jpg) ![Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System - Image 2](https://m.media-amazon.com/images/I/51iMPl2fMIL.jpg) ![Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System - Image 3](https://m.media-amazon.com/images/I/410OrZffd5L.jpg) ![Flowmaster 817637 13-18 Ford Focus St Amt 409s Exhaust System - Image 4](https://m.media-amazon.com/images/I/61n569e5F3L.jpg) ## Available Options This product comes in different **Style** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Some like it loud *by J***. on March 20, 2016* The fact that this is one of the least expensive catbacks available for the Focus ST is what initially drew me to it. I first considered the MBRP catback but it just it was just too quiet. It didn't sound much different than my OEM exhaust with a resonator delete. I also like the fact that you can hear the turbo through the exhaust which is a nice little added bonus that makes it sound even better. This exhaust is loud, one of the loudest non-straight pipe exhausts you can get for the ST. This is mainly due to the fact that is has a single chambered resonator rather than a full-on muffler (basically a steel box with a hole on each end). The end result however is not a nasty, straight-pipe sounding exhaust. It is civil at low rpm's and has a nice deep tone for a 4-cylinder but on the top end once the turbo spools up it will wake the neighbors. Cons: No real cons for me. Interior drone doesn't seem to be much of a problem for me although other people have complained about drone. The interior sound level is not that bad at all and I don't notice much more drone than my stock exhaust with resonator delete. Quality/Install: The system is well designed and feels high quality although some have complained about the exhaust tip bolts being chintzy they seem average to me, so maybe they are using better quality bolts now. I had it installed at an exhaust shop so I can't comment on ease of installation too much aside from reading directions and watching install videos. It appears easy to install but I had a shop do it because I had issues with my jack/stands when I went to do the install myself and just opted to have it installed rather than wait another week.. Price: This exhaust seems overpriced for what it is honestly. It is a single chamber resonator which alone would cost maybe $75 and then about 8 feet of pipe with 2 tips. A good exhaust shop could probably fabricate a similar catback for a fraction of the cost, and the shop I took it to told me they could have gotten me the same system for $430 so SHOP AROUND! You will probably find it cheaper. ### ⭐⭐⭐⭐ Sounds mint i love it. Alittle more drone than i was hoping ... *by D***O on December 27, 2014* Sounds mint i love it. Alittle more drone than i was hoping for. Couldnt for the life of me get the tips to sit even so there alittle lop sided( didnt use a lift. Would have been easier) but i would highly recommend this and would buy again! ### ⭐⭐⭐ Good exhaust, but terrible highway drone *by A***X on April 21, 2015* Sounds great in town. once you go above 65, this exhaust has a terrible drone. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.tn/products/10585568-flowmaster-817637-13-18-ford-focus-st-amt-409s-exhaust](https://www.desertcart.tn/products/10585568-flowmaster-817637-13-18-ford-focus-st-amt-409s-exhaust) --- *Product available on Desertcart Tunisia* *Store origin: TN* *Last updated: 2026-07-26*