BMW
M340i / M440i G20 / G22 · 2020 – present
B58 inline-six wide open at every throttle position — the quiet M-lite finally earns its badge.
- Fits M340i, M340d, M440i, M440d valved exhausts
- No effect on xDrive or adaptive M Sport suspension
- Plug-and-play to OEM actuator
- Reversible — module unplugs in seconds
Free UK shipping
2-year warranty
Fully reversible
The honest pitch
What this actually does to your M340i / M440i
The G20 M340i is one of the best engines in BMW's modern range and one of the most muffled. Even with the Sport exhaust option, the valves spend most of the drive shut.
Open Valve lets the B58 sing the way the M2 lets the B58 sing — straight-six warble on tap, decel pops included.
Fitment
BMW M340i / M440i G20 / G22
Years
2020 – present
Install time
~10 minutes
Tools needed
None
Long read
The BMW M340i / M440i valve story
The G20 M340i is one of BMW's best engines of the modern era and one of the most muffled. Even with the optional Sport Exhaust, the valve map keeps the flap shut at part throttle. Sport+ opens it in narrow bands. The B58 has plenty to say — straight-six warble, decel chatter, the characteristic turbo whoosh — and the factory valve programming keeps most of it hidden until you're at the redline.
Open Valve pins the rear flap open. The B58 then runs in full Sport+ voice in every mode. The M340d (B57 diesel inline-six) supports the same kit. The G22 M440i Coupé and G23 M440i Convertible share the actuator type — same module covers all four.
Single actuator, single module. Install is one of the cleanest in our catalogue — boot floor up, connector accessible from the spare-wheel well. About ten minutes.
Install — step by step
- 01
Lift boot floor and spare-wheel cover.
- 02
Pull back rear right carpet flap.
- 03
Disconnect 2-pin grey connector. Plug module inline.
- 04
Velcro module body to parcel shelf underside.
- 05
Refit carpet, cover, floor.
- 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
- ·G20 M340i, M340d, G22 M440i, M440d, G23 M440i Convertible (2020+) with Sport Exhaust option.
- ·Cars without the Sport Exhaust option do not have a flap to override.
- ·Compatible with M Performance and aftermarket valved back-boxes.
BMW M340i / M440i — FAQ
Does it work on the M340d?+
Yes — B57 diesel uses the same actuator and connector.
What about the M440i Coupé and Convertible?+
Yes — G22 and G23 M440i share the same actuator. Same kit.
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 work without the Sport Exhaust option?+
Cars without Sport Exhaust have a fixed back-box and no flap — the module has nothing to override. Sport Exhaust option required.
Does it interfere with xDrive logic?+
No. xDrive is independent of exhaust valve position.
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.
