BMW M340i G20 / G21 and M440i G22 / G23: the B58 in sedan and coupé form, the exhaust guide
M340i G20 sedan or M440i G22 coupé, the recipe is the same: the B58, a 3.0-liter turbocharged inline-six with 374 hp and 500 Nm (392 hp, 540 Nm since 11/2025), in BMW M Performance models built for everyday use. Their factory exhaust filters out most of it, to the point that you forget what is running under the hood. A single Rog valved exhaust fits both cars; this guide helps you put it together.
Valved Exhaust System for BMW M340i B58 G20 / G21 3.0T (2019+)From $2,839 · free delivery · 20 working days
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Your Rog exhaust for BMW M340i B58 G20 / G21 or M440i B58 G22 / G23
Price shown on the product page, in your currency
Configure my exhaustThe short answer.
- Vehicles
- BMW M340i B58 G20 / G21 (2019+) ; BMW M440i B58 G22 / G23 (2020+). Same exhaust for the G20 sedan and G21 Touring, G22 coupé and G23 convertible
- Engine
- BMW M340i B58 G20 / G21: 374 hp (392 hp since 11/2025) ; BMW M440i B58 G22 / G23: 374 hp (392 hp since 11/2025)
- Prices
- Shown on each model’s product page, in your currency
- 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: BMW 320i G20 / G21 2.0T, BMW 340i B58 F30 / F31 3.0T, BMW 540i B58 G30 / G31 3.0T, BMW 840i B58 G14 / G15 / G16 3.0T.
The 374 hp (392 hp since 11/2025) B58: the straight-six shared by the M340i and the M440i
The B58 is a 3.0-liter inline-six boosted by a twin-scroll turbo, with direct injection. In both the M340i G20 and the M440i G22, it produces 374 hp and 500 Nm (392 hp, 540 Nm since 11/2025), with torque available very early and sustained over a wide range. The engine revs with the smoothness typical of straight-sixes, giving both cars the pick-up of a true sports car.
The M440i is derived directly from the M340i: same engine, same technical base, hence a shared Rog exhaust. An inline-six is naturally balanced and its sound is among the noblest of all; yet the factory exhaust reduces it to a trickle. The Rog exhaust restores its richness with the valves open and preserves the comfort of a grand tourer with the valves closed, with no change to the engine or the ECU.
What makes up the exhaust on your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23
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 BMW M340i B58 G20 / G21 or M440i B58 G22 / G23, from the outlet of the front section to the tips: pipes, muffler, valves. This is the part where most of our research and development goes: it is what shapes the sound, and it is enough on its own to transform the car.
The front section, where the catalytic converter sits
On your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23, it is the downpipe, the pipe leading from the turbo. It contains the factory catalytic converter: the second restriction in the exhaust, after the muffler. Replacing it is optional: it frees up the flow, and it is the ECU remap that turns that into horsepower.
Your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23 in figures
An exhaust system is judged first by ear and on the scales. The extra horsepower comes from an ECU remap.
BMW M340i B58 G20 / G21
Power
Torque
BMW M440i B58 G22 / G23
Power
Torque
Published factory and Stage 2 figures.
The Rog exhaust works with or without an ECU remap. To get the full potential out of your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23, we advise taking it to an approved tuning center afterwards.
The B58 is known for its reserve: at Stage 2, both the M340i and the M440i are quoted at 440 hp and 620 Nm, a result that depends on the car's condition and the quality of the tuning work. The Rog exhaust, which does not modify the ECU, plays no part in this calculation: it gives the tuned engine its voice.
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
Titanium costs more than stainless steel; the price of each version is shown on the product page, in your currency.
304 stainless steel
Baseline
- Weight
- Baseline
- Sound
- Full and rounded
The safe bet: strong, corrosion-proof, with a full, rounded sound. The best value for money.
Titanium
- Weight
- Around 40% lighter
- Sound
- Metallic, crystal-clear
It makes the exhaust around 40% lighter for the same design. Its note is more metallic and clearer higher up the rev range, and its finish ranges from brushed to blued.
No worries on durability: 304 stainless steel shrugs off winter road salt 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 BMW M340i B58 G20 / G21 or M440i B58 G22 / G23, with its catalytic converter. Each option is placed on our sound scale of 0 to 10, valves open, with the factory exhaust at 3.
Cat-back only
Included
7/10Factory emissions control
The factory front section stays in place. It is already a complete transformation, and the choice of many of our customers.
200-cell sports catalytic converter
8/10Road use and inspection
More flow, emissions control retained: the right option for road use.
100-cell sports catalytic converter
9/10Inspection: depends on local rules
More open than the 200-cell: the sound hardens at high revs and emissions control is reduced.
Decat
10/10Track use
Flow with no filter at all: the rawest sound and the sharpest response.
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? With a sports cat, it can come on with some engines: the sensor placed after the catalytic converter measures a different level of emissions control from the original. It is not a mechanical failure, but a warning light should never be masked or cleared without dealing with its cause: the right answer is a catalytic converter suited to the engine, with a map by a tuner who takes it into account. The decat version, for track use only, almost always triggers it. If this happens to you, write to us and we will point you in the right direction. Passing vehicle inspection 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 BMW M340i B58 G20 / G21 or M440i B58 G22 / G23.
Rog remote
A discreet control unit in the trunk and a two-button remote: you open and close whenever you like, independently of the drive modes. For fitting, we support you by email.
Factory control
- Only for vehicles fitted with factory valves
- Controlled by the drive modes
For vehicles fitted with factory valves: the exhaust connects to their control and the drive modes stay in charge, with no extra control unit.
At 130 km/h, many sports exhausts drone. Here, with the valves closed, the exhaust flows through the muffler and stays composed when cruising; open, it makes itself heard when you choose. More about exhaust drone.
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Step 4 of 4: Tips: the visual signature
Match the tips to the style of your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23, 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
- M Performance style carbon
Your choices carry over to the product page: only the finishes, your VIN and the cart remain.
The Rog sound signature on the B58 of the M340i and M440i
The BMW straight-six has a recognizable song: round and even, it climbs smoothly and takes on a more metallic note at high revs. On the standard M340i and M440i, this song arrives muted, as if held at a distance by an exhaust designed first and foremost for passenger comfort.
On this model, two characters at the same price: the straight pipe for the raw sound of your engine, unfiltered, or the resonator for a rounder and slightly softer voice. Either way, the exhaust stays fully sporty.
With the valves open, the Rog exhaust lets the B58 express itself fully: a start-up that announces itself, a crisp climb through the revs and sharp crackles on the overrun. With the valves closed, both sedan and coupé return to factory discretion, for the daily commute and long distances.
From order to fitting
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Configuration
You configure the exhaust and enter the VIN from box E of your registration document or from the base of the windshield.
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Check
Your VIN is checked before any manufacturing begins.
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Manufacturing
The exhaust is produced to order, for your vehicle.
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Delivery
Free, insured parcel, tracking number from dispatch.
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Fitting
Around two hours in the workshop, with no welding or cutting.
20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship, from the date of purchase
- Payment
- Card, PayPal or bank transfer
- Installation
- At the garage of your choice
Is your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23 still under the manufacturer's warranty? In Europe, the manufacturer cannot refuse cover simply because a part from another brand has been fitted: it is up to the manufacturer to prove that the fault comes from that part. Our article on the manufacturer's warranty.
Our recommendations for your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23
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Daily driving
- Stainless
- Cat-back only
- Rog remote
Your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23 stays easy to live with, the factory emissions control is retained, and you open the valves whenever you decide.
View this configuration -
Fast road
- Titanium
- 200-cell downpipe
- ECU remap
The best of both worlds: character and breathing, with emissions control retained.
View this configuration -
Track
- Titanium
- Decat downpipe
- Stage 2
The most extreme configuration, for track use only.
View this configuration
Every BMW M340i B58 G20 / G21 or M440i B58 G22 / G23 has its own story and its own use: if none of these profiles sounds like you, let's talk.
BMW M340i B58 G20 / G21 or M440i B58 G22 / G23: your questions
How much power does an exhaust add on the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23?
As standard, the BMW M340i B58 G20 / G21 produces 374 hp (392 hp since 11/2025); the BMW M440i B58 G22 / G23 produces 374 hp (392 hp since 11/2025). The exhaust alone acts first on sound, breathing and weight; the extra horsepower comes from an ECU remap. The published Stage 2 figures for each model are shown in the figures table.
Stainless steel or titanium: which material for the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23?
The Rog exhaust comes in stainless steel and titanium, at the price shown on the product page in your currency. Stainless steel is the safe bet, with a full sound; titanium makes the exhaust around 40% lighter and gives a more metallic note higher up the rev range.
Do you need to replace the catalytic converter on the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23?
It is not compulsory. The cat-back alone is enough to change the character of the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23. Replacing the downpipe is how you go further, together with an ECU remap: 200 cells for the road, 100 cells or decat for more radical use.
Will a Rog exhaust pass vehicle inspection on the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23?
The cat-back only and the 200-cell converter both retain emissions control: present the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23 with the valves closed. With the 100-cell, acceptance at the emissions test depends on the car and local rules; the decat is intended for track use.
How is the Rog exhaust fitted on the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23?
With clamps and gaskets, no welding or cutting: around two hours in the workshop for a well-equipped mechanic. The exhaust is built to the VIN of your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23.
What price and lead time for a Rog exhaust on the BMW M340i B58 G20 / G21 or M440i B58 G22 / G23?
The price depends on the configuration and is shown on the product page, in your currency. Allow 20 working days from order confirmation to delivery. Delivery is free and the exhaust comes with a 3-year warranty.
Valved Exhaust System for BMW M340i B58 G20 / G21 3.0T (2019+)
From $2,839 · 3-year warranty
Configure my exhaustUnsure about your configuration? Write to us.
Stainless steel or titanium, cat-back only or the complete system: the right choice depends on how you drive and on your BMW M340i B58 G20 / G21 or M440i B58 G22 / G23. We take the time to talk it through before you order, with a reply within 24 hours. We are not here to push a sale: we help you choose, even if that means a cheaper option because it suits the way you drive. Write to us: we reply in writing, in English.
Rog is a French brand, and the way we work comes down to one idea: an exhaust system should be sold with advice, not just a product page. More than 500 exhaust systems fitted and a rating of 4.9 out of 5.
Further reading
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