Ford Focus ST MK4: unleashing the EcoBoost, the complete exhaust system guide
The Focus ST MK4 is one of the most accomplished hot hatches of its generation: a sharp chassis and 280 hp full of torque. Its factory sound is too tame for its temperament: the ST community says so, and we fix it. For your Ford Focus ST MK4, this guide sets out what each choice changes: material, front section, sound, valves and fitting.
Written by ROG Motorsport · Updated
Your ROG exhaust for the Ford Focus ST MK4
From €2,405 in stainless steel, €3,005 in titanium
Configure my exhaust- Vehicles
- Ford Focus ST MK4 (2019+)
- Engine
- 280 hp · 420 Nm
- Exhaust
- Valved cat-back, built for your VIN
- Material
- 304 stainless steel or titanium
- Front section
- Optional: catted downpipe with 200 or 100 cells, or decat
- Valves
- ROG remote, or factory control if your vehicle has it
- Lead time
- 20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship
Closely related versions have their own guide: Ford Focus RS Mk3 2.3 EcoBoost.
The EcoBoost: the Ford turbo that responds instantly
The EcoBoost engine in your Focus ST MK4 is a modern turbo with real character: sharp response, generous torque and an extremely popular tuning base in the Ford community. Its factory sound, calibrated to meet the standards, does not tell of that temperament: it is the first thing the community modifies, and for good reason.
The ROG exhaust gives the EcoBoost a full, snarling voice, with crisp crackles on the overrun with the valves open, and the factory discretion with the valves closed.
How the exhaust on your Ford Focus ST MK4 is put together
An exhaust system is best understood in two parts. Here is what each one does, and what ROG replaces.
The cat-back is the complete exhaust system
It is everything you can see under your Ford Focus ST MK4, from the outlet of the front section to the tips: pipes, silencer, valves. This is where our research and development is focused, and it is what shapes the sound. On its own, it changes the character of the car.
The front section, where the catalytic converter sits
On your Ford Focus ST MK4, this is the downpipe, the pipe that leads away from the engine. It contains the factory catalytic converter: the second restriction in the exhaust, after the silencer. Replacing this part is optional: it frees up the flow, and an ECU remap is what turns that into power.
Your Ford Focus ST MK4 in figures
On a modern car, an exhaust system first changes the voice, the breathing and the weight at the rear. Power, on the other hand, comes from an ECU remap.
Power
Torque
Published factory and Stage 2 figures.
Our exhaust systems work perfectly with or without an ECU remap. On your Ford Focus ST MK4, however, we recommend one at an approved tuning centre: it is what lets the engine deliver its full potential.
Let's be frank: the exhaust alone brings a moderate gain. The EcoBoost, on the other hand, is one of the best Stage 2 bases in its class: with an ECU remap at an approved tuning centre, the figures above are widely documented by a huge community.
Configuring your exhaust, step by step
4 choices, in the same order as the product page configurator.
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Step 1 of 4: Material: stainless steel or titanium
For your Ford Focus ST MK4, the exhaust costs €2,405 in stainless steel and €3,005 in titanium.
304 stainless steel
2 405 €
- Weight
- Baseline
- Sound
- Full and rounded
The benchmark for high-end exhausts: tough, corrosion-proof, with a full, rounded sound. The choice of most of our customers.
Titanium
3 005 €
- Weight
- Around 40% lighter
- Sound
- Metallic, crystal-clear
Around 40% lighter than stainless steel for the same design, with a more metallic sound that turns crystal-clear at high revs. Its finish ranges from brushed to blued tints.
Over time, both hold up: 304 stainless steel stands up to winter salt and damp, and titanium does not rust. Stainless steel or titanium: what really changes.
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Step 2 of 4: Front section: downpipe and catalytic converter
Optional: the downpipe on your Ford Focus ST MK4, with its catalytic converter. Sound intensity is rated on our scale of 0 to 10, valves open; the factory exhaust scores 3.
Cat-back only
Included
7/10Factory emissions control
The factory catalytic converter stays in place. The starting point and, for many of our customers, more than enough.
200-cell sports catalytic converter
+760 €
8/10Road use and French MOT
Emissions control is still very much there, and flow improves noticeably. The choice for everyday driving.
100-cell sports catalytic converter
+760 €
9/10French MOT pass not guaranteed
Half as many cells: flow comes close to a decat and the sound gains real aggression at high revs.
Decat
+565 €
10/10Track use only
No emissions control: maximum flow, raw sound, the sharpest revving.
Sound intensity, on a scale of 0 to 10
- 10/10Decat downpipe + ROG cat-back
- 9/10100-cell sports catalytic converter + ROG cat-back
- 8/10200-cell sports catalytic converter + ROG cat-back
- 7/10ROG cat-back only, factory catalytic converter retained
- 3/10Factory exhaust, for comparison
Valves open. With the valves closed, every configuration becomes discreet again.
What about the engine warning light? A sports catalytic converter can trigger it: the oxygen sensor after the catalytic converter detects less cleaning than with the factory unit. It is not a fault. An ECU remap recalibrates the sensor, and a session with a diagnostic tool clears the fault code. With a decat, the warning light is almost certain without a remap. If it happens to you, call us and we will point you in the right direction. Passing the French MOT with a sports exhaust.
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Step 3 of 4: Valves: ROG remote or factory control
Two ways to control the valves on your Ford Focus ST MK4.
ROG remote
A small control unit fits in the boot. Two buttons, open and closed: the valves respond at any moment, whatever the drive mode. Simple to fit, and we stay on hand throughout the installation.
Factory control
- Only for vehicles fitted with factory valves
- Controlled by the drive modes
If your vehicle is fitted with factory valves, the exhaust keeps their existing control. The drive modes decide, just as they did from the factory, with no added electronics.
On the motorway, with the valves closed, the gases pass through the silencer, designed for cruising: no drone at a steady speed. You open up when you feel like it, not when the motorway decides for you. More about exhaust drone.
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Step 4 of 4: Tips: the visual signature
Match the tips to the style of your Ford Focus ST MK4, understated or bold. A particular finish in mind? Send us a photo and we will look at it together.
- Stainless steel
- Black
- Carbon
- Blued titanium
The ROG sound signature on the EcoBoost
Our exhaust gives the EcoBoost a full, snarling voice: an assertive sporty tone, an audible turbo, and crisp crackles on the overrun with the valves open. With the valves closed, the factory discretion returns in full for everyday driving.
From order to fitting
-
Configuration
You choose your exhaust and enter your VIN, found in box E of your registration certificate.
-
Check
We check compatibility with your VIN before manufacturing begins.
-
Manufacturing
Your exhaust is made to order, for your car.
-
Delivery
Free in Europe, insured to your door, tracked from dispatch.
-
Fitting
No welding or cutting: clamps and gaskets, around two hours on a lift.
20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship, from the date of delivery
- Payment
- In instalments with Klarna
- Installation
- At the garage of your choice
What about the manufacturer's warranty on your Ford Focus ST MK4? In Europe, a manufacturer cannot refuse warranty cover simply because a part from another brand has been fitted: it has to prove that the fault comes from that part. Our article on the manufacturer's warranty.
Our recommendations for your Ford Focus ST MK4
-
Daily driving
2 405 €
- Stainless
- Cat-back only
- ROG remote
Your Ford Focus ST MK4 stays easy to live with, the factory emissions control is retained, and you open the valves when you decide.
View this configuration -
Fast road
3 760 €
- Titanium
- 200-cell downpipe
- ECU remap
More sound, more breathing, and a car you can still present at the French MOT.
View this configuration -
Track
3 575 €
- Titanium
- Decat downpipe
- Stage 2
The most extreme configuration, for track use only.
View this configuration
And if you are still unsure, that is perfectly normal: it is exactly why we answer the phone.
Ford Focus ST MK4: your questions
How much power does an exhaust add on the Ford Focus ST MK4?
As standard, the Ford Focus ST MK4 produces 280 hp and 420 Nm. An exhaust system on its own mainly changes the sound, the breathing and the weight; power is gained with an ECU remap. With a Stage 2 build, the published figures reach 350 hp and 510 Nm.
Stainless steel or titanium: which material for the Ford Focus ST MK4?
For the Ford Focus ST MK4, the ROG exhaust costs €2,405 in stainless steel and €3,005 in titanium. 304 stainless steel is tough, rounded in tone and the most popular choice; titanium is around 40% lighter for the same design, with a more metallic sound at high revs.
Do you need to replace the catalytic converter on the Ford Focus ST MK4?
No. On the Ford Focus ST MK4, the cat-back alone carries the valves and already transforms the sound. Replacing the downpipe is an option for going further: with a 200-cell sports catalytic converter for the road, 100-cell or decat for more radical use, with an ECU remap to turn it into power.
Does the Ford Focus ST MK4 pass the French MOT with a ROG exhaust?
With the cat-back only or the 200-cell sports catalytic converter, emissions control is retained: present the car with the valves closed. The 100-cell converter no longer guarantees a pass, and the decat fails the emissions test.
How is the ROG exhaust fitted on the Ford Focus ST MK4?
No welding or cutting, using clamps and gaskets. Allow two hours on average for a well-equipped mechanic. The exhaust is built for your VIN, which guarantees compatibility before it ships.
What price and lead time for a ROG exhaust on the Ford Focus ST MK4?
From €2,405 to €3,760 depending on the configuration. Allow 20 working days from order confirmation to delivery. Free delivery in Europe and a 3-year warranty.
Unsure about your configuration? Give us a call.
Stainless steel or titanium, cat-back only or the complete system: the right choice depends on how you use your Ford Focus ST MK4. We take the time to talk it through before you order, with a reply within 24 hours. We are not here to sell to you over the phone: we help you choose, even if that means a cheaper option because it suits the way you drive.
RogMotorsport is a French brand built on one conviction: with an exhaust system, the support matters as much as the product. More than 500 exhaust systems fitted and a rating of 4.9 out of 5.
Further reading
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