Focus ST Exhaust – FAQ & Buyer’s Guide for Ford Owners!

The Ford Focus ST is an enthusiast car like no other. It’s a speedy little hatchback that can easily beat out expensive sports cars on windy roads and provide for a fun and hyper-engaging driving experience.

It’s no secret that one of the absolute best ways to improve the driving experience of any car is by swapping out the stock factory exhaust for a custom exhaust system. Aside from the awesome power gain in the form of added horsepower and torque, the totally different sound it emits adds a whole new character to the car, as well as a refreshed dynamic to your driving experience.

With Borla being one of the top exhaust manufacturers for some of the coolest cars under the sun — I’m not surprised that their 140504 Cat-Back Exhaust System made it to the top of our list. Whether you’re looking for the added power boost, or are simply trying to save a bit more fuel with a regulated emission exhaust system — this one has both bases covered.

It fits like a glove, and is also practically indestructible, thanks to the fact that it’s made out of austenitic stainless steel. This also makes this exhaust one of the lightest on our list, coming in at a mere 30lbs. Good news for the folks who like a low ride! No more having to worry about cracking your exhaust or scraping the life out of it over speed bumps.

While both the amazing fit and lifelong durability are definitely a big plus, this exhaust really shines in performance. Just like Borla’s motto “sound like heaven, ride like hell”, this exhausts packs a mean power boost. And it sounds stellar! All while being completely compatible with emissions regulations.

Last (but definitely not least), the whole exhaust system is incredibly easy to install. For those of us who like to put in work into our rides, that’s some great news.”] When it comes to picking out the best exhaust for your Focus, you’ll quickly realize that there’s a whole myriad of options available. As you get to contrasting their differences (which are microscopic at times), the whole endeavor can quickly become an overwhelming quest.

Focus ST Exhaust  — Comparison Table

Best Overall Exhaust
Borla 140504 review
Borla 140504
  • Austenitic Steel
  • 30 lbs
  • Absolutely no drone
  • Painless installation
  • Sleek and polished finish

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Significant Power Boost
MagnaFlow 15155 review
MagnaFlow 15155
  • Stainless Steel
  • 40.1 lbs
  • Gorgeous polished finish
  • Moderate to aggressive sound that isn’t obnoxious
  • Straightforward, easy install process

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Easy To Install
  • Stainless Steel
  • 30 lbs
  • Rich & Loud
  • Beautifully polished
  • Mandrel Bent Tubing

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To save you both money and time in your effort, I’ve put together a detailed guide. I will cover every aspect you should be aware of when it comes to picking out a new system, and I’ll even provide our top picks for the best Focus ST exhausts to help you narrow down your list.

Review of Top-Rated Focus ST Exhaust Systems:

1. Borla 140504 – Best Ford Focus ST Exhaust

Overall — I’d like to think that this is probably the best exhaust for the Focus ST on the market.. It’s a bit quieter than some of the other exhausts I’ve mentioned in our top picks, but that doesn’t take away from this exhaust being amazing in every way.

The exhaust tone is in no way an obnoxious system, and the noise output is only 1-2 decibels louder than your stock exhaust system when sitting at idle. However, despite seeming meek and shy at first glance, this system can fully produce that head-turning growl many of us are after.

It’s diverse and can provide that satisfying roar when putting the pedal to the metal, but it can also afford a moderate hum while driving around town. Depending on your speed and throttle, this system will purr, growl, or roar. In other words, if you want to be quiet with this system, you can be, and if you want to be heard, it’ll sing.

Are you wondering about its build quality and performance? This exhaust is built using austenitic steel. This means it can take quite a hit (or scrape) without flinching, many times over. In turn, it also means that if you’re riding low, you can relax knowing that your exhaust isn’t about to crack or get banged up.

However, that’s not to say that it’s on the durability level of a titanium exhaust, so I’d definitely advise choosing what works best for you on a personal level.

In terms of power, it’s no slouch, either. With older Focus ST models clocking in around 250 horsepower, Borla claims this exhaust can add 7-10% gains. Grade 2 math tells us that it would imply gains of up to 25 horsepower. According to the myriad of buyer reviews, these claims actually hold up!

We’re sure many of you are wondering about the ease of installing this awesome exhaust. And you’re in luck! The Borla 140504 Cat-Back system is incredibly simple to install. In fact, you can easily do it yourself — no need to take it to a shop if you have a basic understanding of the installation process.


  • 304 stainless steel
  • Lightweight at just 30 lbs
  • 4 ½“ Dual tips that extend further than the stock exhaust system
  • 2-1/2″ Mandrel Bent Piping
  • Bolt-on installation
  • Touring-style muffler
  • No resonator included on this exhaust kit


  • Absolutely no drone
  • Painless installation
  • Sleek and polished finish
  • Will not rust for a LONG time due to steel quality
  • Big power gain
  • Very dynamic exhaust sound with a nice tone

2. MagnaFlow 15155 – Best Performance Exhaust for Focus ST

The MagnaFlow 15155 Performance exhaust system will fit perfectly on your car, no welding required. In fact, it easily bolts on to replace your old exhaust system and can be fitted in under an hour.

Possibly the main feature that MagnaFlow advertises is the supposedly “aggressive” exhaust sound. Personally, we found the sound to be pretty moderate. It’s not quite as toned down as the Borla 140504 Cat-Back Exhaust, but it’s not overwhelming either.

It produces a deep and pleasant rumble that will turn heads and get your Focus ST the right amount of attention at car meets, all without waking your neighbors if you roll into your driveway at night.

This exhaust will give you the louder growl upon acceleration, but is not so loud that it overpowers the nice rumble and deep sound of the engine. No 4-cylinder rasp, no annoying exhaust drone, only pure pleasure.

MagnaFlow 15155 Large Stainless Steel Performance Exhaust System Kit
  • Straight through mufflers
  • Mandrel bent tubing
  • Stainless steel construction
  • Dyno-proven power

In terms of build quality — it’s definitely up there! This is a solid stainless steel exhaust with metal that feels relatively thick and sturdy. The welds are done neatly and nothing looks out of place out of the box. It also fits nicely, so it’s easy to tell that MagnaFlow puts a lot of care into these exhausts. The polished steel tips add a nice aesthetic touch, providing for some decent style points.

Now, let’s talk about power! MagnaFlow put it’s 30 years of expertise in creating awesome performance exhausts into testing these exhausts on the dyno to optimize the weight and find a perfect balance between power, durability and amazing sound. In our opinion, they’ve definitely done a great job in this department.

While it’s tough to put a finger on just how much horsepower this exhaust adds to your Focus ST, the fact that this is a straight-flow exhaust implies an undeniable power boost. This, we believe, is the real highlight of this exhaust. You get to enjoy a serious increase in both horsepower and low-end torque, without having to sacrifice exhaust efficiency.

If you consider their lifetime warranty against manufacturing defects, along with its very comfortable price-point, it’s definitely one of the best exhausts you can get for your Focus ST.


  • 2.5” piping diameter of mandrel bent piping
  • Bolt-on installation
  • Dual rear center exit point featuring stock tip
  • Two mufflers
  • Street series components featuring 409 stainless steel
  • 5”X14” resonator included


  • Gorgeous polished finish
  • Moderate to aggressive sound that isn’t obnoxious
  • Straightforward, easy install process
  • Increases horsepower with straight-through design
  • Improves motor efficiency

3. SRS Tuning SRS-CBEX-FOCUSST – Stainless Steel Exhaust for Focus ST

The SRS Type-R1 Catback Exhaust System for the 2013-2018 Ford Focus ST 2.0L Turbo 3 is an excellent import option with a lower price tag. The Japanese brand SRS produces beautifully polished and incredibly reliable T-403 stainless steel mandrel bent tubing. If you’re looking for a gorgeous, easy-to-install exhaust, this is a great choice.

Out of the box there’s no welding required for installation; just remove your stock exhaust and this bolt-on solution will perfectly fit into place. In fact, I’d go as far as to say that it’s the easiest exhaust to install out of all the options on this list.

The tone of the SRS Type-R1 Catback Exhaust System is incredibly deep and rich. Yet, it’s outstandingly loud in comparison to your stock exhaust system. This exhaust will turn heads, and without an overly dynamic range like the one you’d find in a Borla 140504 Cat-Back Exhaust, you’ll be able to enjoy a vibrant deep growl, no matter the revs.

  • Compatible For 13-19 Ford Focus ST 2.0L
  • Direct bolt on design
  • Full T-304 Stainless Steel
  • Mandrel bent tubing
  • Japan design

However, if this bothers you — there’s an easy fix. You can simply install another muffler and consider different tips if you’re looking for a quieter ride. In terms of the drone, I’m happy to say that there is none, which is the standard when it comes to many Japanese performance exhausts.

Adding to the already very solid build quality, one of the most surprising things about this exhaust is the fact that the weld-marks are nearly seamless. This only adds to the already significant aesthetics of this particular exhaust.

Looking at power, it doesn’t disappoint! You can expect a significant out-of-the-box horsepower increase of up to 15HP. Though this may not seem like much upfront, taking your Focus ST from around 250HP to 265+ is actually a very pronounced difference, which changes the entire character of your car.


  • Incredibly simple bolt on installation
  • Mandrel Bent Tubing
  • High Japanese build quality
  • 3” Piping with 4” Dual Tip
  • 14” weld To weld, providing a loud sound


  • Rich & Loud
  • Beautifully polished
  • Japanese design with simple welds
  • Bolts on with ease
  • Rarely drones

4. MVP Auto Parts SS SS409 – Best Cat Back Exhaust for Focus ST

The 3” Stainless Steel SS SS409 Cat-back Exhaust system by MVP Motors is a fantastic budget alternative to some of the better known brands. It delivers a great power boost, and despite having a few minor kinks (it is a budget option after all), it’s still a great option if you want to up your game without breaking the bank.

The sound of this thing all depends on how hard you decide to push the engine. If you’re in a low gear and headed up-hill, you can expect a rambunctious exhaust tone. Otherwise, it’s relatively tame.

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While it doesn’t have an incredibly rich exhaust note like the Flowmaster 817637, it’s not obnoxious by any means. One thing that surprised us quite a bit was that there was no drone. Given the price of this exhaust, this fact definitely gives it some bonus points.

The installation process is fairly straightforward, but it may not be a perfect fit without some work, as it’s only made to fit on the ST 4-door hatchback model. Given the price, one of the things that is to be expected is some variation in fitment, as evidenced by some of the buyer reviews online.

Despite this, it’s still relatively easy to install and fit if you clamp it down properly. Or, you can just have a shop install it for you altogether.

In the looks department, it doesn’t offer anything special or stellar. Given the low price-point, it comes in a simple brushed steel finish, with only the tips being polished. But don’t let this deter you! Despite the less-than-sexy finish and some occasional kinks with fitment, it’s a very solid exhaust.

Made with 409 stainless steel, it’s practically a tank in its own right. Since the body is not chromed out or polished, the occasional scratch or scrape will go practically unnoticed.

Overall, this exhaust kit is undeniably worth your money and is great for anyone looking for a very budget-friendly entry option to getting a new exhaust for their Focus ST.


  • 3” Stainless Steel SS SS409 Dual Cat Back Exhaust Kit System With Performance Mufflers & Polished Tips
  • Fits ‘13-19 Ford Focus ST 4-Door Hatchback EcoBoost Turbocharged
  • TIG Weld & Mandrel-Bent Steel pipe
  • 3” Inlet to 3” Tailpipe
  • All Bolts, hangers and clamps included


  • No drone
  • Easy Installation on 4-Door Hatchback Focus ST
  • Moderate, understated tone
  • Perfect for hobbyists
  • Low price

5. Flowmaster 817637 - Exhaust for 2013-2018 Focus ST

This exhaust system is perfect for those who like their ride to be a bit on the louder side. If you’re not worried about waking up the neighbors, you won’t have a problem with the volume of this exhaust at higher RPM’s.

This system produces a loud rumble due to a single-chamber resonator. It doesn’t feature a full-on muffler, which means it emits a very aggressive sound, even when cruising.

However, it is still quieter than most straight exhaust systems, and I'd call it moderately civil at lower speeds and RPM’s. So, whether you’re just cruising around or showing off at a meet with friends, this exhaust has plenty to offer in all capacities of the sound department. Despite being moderately aggressive, the sound is deep and sporty rather than flat and obnoxious.

They also designed this system to improve your Focus ST’s power output, and it definitely does not disappoint. Without any engine modifications, this exhaust system packs a punch in the form of an out-of-the-box increase in horsepower.

Flowmaster 817637 American Thunder Cat-back Exhaust System
  • Lifetime Limited Warranty
  • Great Performance Sound
  • Dyno Tuned For Maximum Performance
  • Stainless Steel Construction

It really changes the feel of the car, making it a whole new beast altogether. With the solid 409 stainless steel built, it’s also one of the most durable exhaust options for your Focus.

However, unlike some of the other exhausts I've covered, it’s a bit heavier, weighing in at 48 lbs. But, unless you’re planning on stripping your car and riding bare bones for ultimate weight reduction, it doesn’t create a significant weight difference that you’ll be able to feel.

If you’re looking for a great all around exhaust that offers increased mileage, good power gains, robust sound, and improved throttle response — this one’s a great pick!


  • Dyno Tuned
  • Performance sound
  • 409 Stainless steel construction which means no rust
  • A bit heavier than others on our list at 48 lbs
  • 3 ¼” polished tips


  • Loud but not obnoxious or raspy
  • Competitive price
  • Straightforward installation process, you can do it yourself with a lift and the appropriate tools
  • Designed for an easy fit, every time

Focus ST Exhausts — Buyer’s Guide

How to Make Your Focus ST Exhaust Pop

If you’re driving a Focus ST with an exhaust mod, you’ll likely notice that your exhaust burbles and pops from time to time. Generally speaking, with most aftermarket exhausts that you can buy, you won’t need a tune to get it popping.

This normally happens around the 3,000-4,000 RPM mark, so all you’d need to do is throw your car in a lower gear (say 2nd or 3rd gear for example), and punch the throttle a bit.

How to Remove Your Focus ST Exhaust

If it’s outside of your realm of expertise, you may be wondering how to get started on getting your stock exhaust off of the car.
Luckily, it’s incredibly easy!

You’ve got two options available. If you’re not DIY inclined and want to take it into a shop, they would typically remove the rear suspension, which allows the stock exhaust to be removed without any cutting involved. If you’d like to resell the stock exhaust, or keep it as a backup option, that’s probably the best route to go.

However, if you’re ok with cutting it — then all you need to get started is a sawzall (otherwise known as a reciprocating saw) with a metal-cutting blade. Carefully, without damaging other components of your car, you just need to cut the stock exhaust off, making your car ready to install the new one.

On the flip side, if you’re removing an exhaust from a used car that’s already had the stock exhaust installed — you should first identify the brand of the exhaust to get a clearer picture of how it was installed. With some exhausts, it’s as simple as removing a few bolts, while with others you may need to stick to the original plan of hacking it off with a reciprocating saw.

How to Clean Your Focus ST Exhaust

Most of us who own cars with modified exhausts love the brilliant sheen of our exhaust tips. It’s almost a shame to see them blacken over time. The cheapest solution is actually a five dollar purchase at any hardware store. Grab yourself a degreaser and some metal polish along with a pack of steel wool.

Before you get started, remember to throw on a pair of gloves to protect your hands!

As a first step, you should give your exhaust tips a nice in and out scrub with hot water and soap. Once that’s done, just apply the degreaser and work away at the buildup with some steel wool. Let it sit for a little while before removing it, and once it’s removed, take a cloth with some metal polish to the exhaust tips.

Voilà! Your exhaust tips look as gorgeous and shiny as the day you took delivery.

Where to Cut Your Focus ST Exhaust

When you’re removing your stock exhaust, you might not know where exactly to cut it in an effort to get it off of your car. If you follow the exhaust piping to the end, you need to cut it closest to the subframe. Make sure to do so while avoiding the other crucial components like the joints or anything else that doesn’t belong to the exhaust system.


There you have it! This concludes my review of the five best Focus ST exhausts on the market right now. We’ve gone over the most important aspects of each exhaust and highlighted the most important things to be aware of when you’re looking at each option.

I hope that my guide helped you get a better grasp on what it is that you want out of your new exhaust system. And hopefully, I've managed to give you a few new ideas and some inspiration on potential exhaust systems that you can put on your short-list in your quest to pick out the best possible exhaust for your car.