Ford
Focus RS MK3 · 2016 – 2018
Make the Mountune-friendly 2.3 EcoBoost finally sound like it should from the bumper out.
- Fits MK3 Focus RS valved exhaust
- Compatible with Mountune and Milltek valved systems
- No effect on Drift Mode or AWD logic
- Plug-in install with no harness mods
Free UK shipping
2-year warranty
Fully reversible
The honest pitch
What this actually does to your Focus RS
The MK3 RS arrived with a soundtrack everyone thought would get louder over the years. Then Ford's emissions updates went the other way.
Open Valve gives you back the launch-spec growl on tap, with the factory pipework still in the boot floor.
Fitment
Ford Focus RS MK3
Years
2016 – 2018
Install time
~10 minutes
Tools needed
None
Long read
The Ford Focus RS valve story
The MK3 Focus RS arrived with a soundtrack everyone expected to keep growing louder over the years. Ford went the other way — the late-cycle ECU updates muted the valve programming considerably, especially around Drift Mode. The 2.3 EcoBoost was always more vocal than it sounded out of the bumper.
Open Valve restores the launch-spec valve behaviour. The RS then crackles on lift, snarls in midrange and pops between gears the way it did on the launch fleet press drives. Mountune-tuned cars and Stage 2 builds sound considerably angrier — the blow-off and the bigger turbo response come through the back-box without the damping.
Single actuator, single module. Install is straightforward — about ten minutes behind the rear bumper.
Install — step by step
- 01
Lower the rear of the offside wheel-arch liner.
- 02
Locate the 2-pin valve actuator connector on the rear silencer.
- 03
Disconnect, plug module inline.
- 04
Velcro module body to chassis rail.
- 05
Refit liner.
- 06
Pair fob, test.
In the box
- One valve override module (one per actuator)
- Two-button RF key fob (CR2032 pre-installed, spare in the box)
- OEM-pattern connectors — no cutting, no splicing, no scotch-locks
- Printed install card with model-specific photos and a workshop QR link
Fitment notes
- ·MK3 Focus RS (2016–2018) — all model years supported.
- ·Compatible with OEM, Mountune and Milltek valved back-boxes.
- ·Straight-through track exhausts without flaps are not compatible.
Ford Focus RS — FAQ
Does it work with Mountune or Milltek valved back-boxes?+
Yes — both use the OEM actuator type. Same connector, same kit.
Will it affect Drift Mode or the AWD logic?+
No — those systems are unaffected. The module only touches the valve actuator signal.
Will it throw a warning light on the dash?+
No. The module sits in the signal path between the ECU and the actuator motor. The ECU sees a normal actuator response back, so there's nothing to flag. We've shipped thousands of these and not had a single check-engine call linked to the module itself.
Is it reversible?+
Yes, fully. Unplug the module, plug the OEM connectors back into each other, refit the trim — about three minutes' work. There's no permanent change to the car, no part cut, nothing in the ECU. Dealer service visits, MOT, sale to a new owner — pull it out and it's like it was never fitted.
Does it work with an aftermarket exhaust?+
If the aftermarket back-box retains the OEM-pattern valve actuators (most do — Akrapovic, Milltek, IPE, Capristo all run the factory motors), yes. If the system is a straight-through with no valves, there's nothing for the module to override.
Will Ford dealer diagnostics see anything?+
No. The module is invisible to IDS.
Does the cabin Active Noise come back louder?+
Active Noise Cancellation in the cabin reads cabin microphones and tries to cancel low-frequency drone. It will continue to do its job — the cabin doesn't get drone-y, it just gets the more vocal exhaust note bleeding in.
Disclaimer
Open Valve modules are intended for off-road and motorsport use only. Please confirm your car has factory valve-actuated exhaust before ordering — if you're not sure, message us first. Professional installation recommended. Use at your own risk.
