Audi
RS4 Avant B9 / B9.5 · 2017 – present
Free the 2.9 TFSI twin-turbo V6 in the only RS Avant most of us can actually afford.
- Fits B9 and B9.5 RS4 Avant
- Two-module pair, plug-and-play
- Doesn't touch quattro or DRC logic
- Reversible, no coding required
Free UK shipping
2-year warranty
Fully reversible
The honest pitch
What this actually does to your RS4 Avant
The B9 RS4 shares its engine with the RS5 and shares its frustration with every other emissions-era RS car: brilliant noise, hidden behind a conservative valve map.
Open Valve lets the V6 breathe through the OEM tips at any RPM. The crackle on lift comes back like the launch-spec car.
Fitment
Audi RS4 Avant B9 / B9.5
Years
2017 – present
Install time
~10 minutes
Tools needed
None
Long read
The Audi RS4 Avant valve story
The B9 RS4 Avant shares its 2.9 TFSI twin-turbo V6 with the RS5 and shares the same conservative valve map. The estate body adds resonance the coupé doesn't have — the RS4 is, in our view, the better-sounding car when you let it go. The valve programming just doesn't let it go often enough.
Open Valve pins both rear flaps open. The V6 then runs with the full midrange swell and decel snap-crackle the launch cars had. B9 and B9.5 both supported.
Two-module kit, install via the boot floor — about fifteen minutes.
Install — step by step
- 01
Boot floor up, styrofoam tray out.
- 02
Pull back carpet flap, locate both 2-pin connectors near the rear silencer.
- 03
Disconnect each, plug modules inline.
- 04
Velcro module bodies to parcel shelf underside.
- 05
Refit carpet, tray, floor.
- 06
Pair fob, test.
In the box
- Two valve override modules (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
- ·B9 RS4 Avant (2017+), B9.5 RS4 Avant facelift (2020+), RS4 Competition (2023+) — all supported.
- ·Compatible with Capristo and Milltek valved aftermarket back-boxes.
Audi RS4 Avant — FAQ
Does it work on B9 and B9.5?+
Yes — pre-facelift and facelift share the same actuator hardware. Same kit.
What about the RS4 Competition?+
Yes — RS4 Competition uses the same actuator type. Same install.
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 it interfere with quattro sport differential?+
No. The sport rear diff is electronically controlled from steering and torque sensors. Independent of exhaust.
Does dealer diagnostics see the module?+
No — invisible to ODIS.
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.
