Does the AFlow Catted Downpipe for B58 need a tune?

No. Active Autowerke sells the AFlow Catted Downpipe for B58 BMW models as a no-tune part, and its two-year catalyst efficiency guarantee applies on factory software. A tune will extract more from the extra flow, but the downpipe does not need one.

Will it cause a check engine light?

Active Autowerke guarantees the AFlow converter against catalyst efficiency codes for two years of ownership, with full replacement if one appears. The converter reaches working efficiency within 9 seconds of a cold start, so the rear oxygen sensor reads a working catalyst almost at once.

Does it fit 2025 and newer B58 models?

No. This downpipe covers B58 vehicles through the 2024 model year. The updated B58 engine in 2025 and newer vehicles needs a different Active Autowerke downpipe, and the 2025 and newer M340i and M440i have their own version again, so check the model year before ordering.

Is the downpipe hard to install?

No cutting or welding is needed. The downpipe seats on a cast stainless V-band at the turbo, the gasket arrives already fitted, and the 80mm outlet meets the factory exhaust. A lift makes the job easier, and the stock part can go back on later.

How does the AFlow version differ from the GESI version?

The stainless pipework is identical. The AFlow version carries an Active AFlow converter rated for up to 800 horsepower plus a two-year code guarantee. The GESI version carries a GESI G-Sport converter rated from 500 to 850 horsepower and sells for more.

Description

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BP PRICING DIFFERENCE

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Description

Active Autowerke AFlow Catted Downpipe for B58 BMW 2 to 7 Series, X3, X5 and X7 (2024 and Older)

Active Autowerke’s AFlow Catted Downpipe for B58 BMW models built through 2024 opens up the single-turbo inline six with a 4.5 inch stainless main section and a matching 4.5 inch Active AFlow converter, then steps down to the factory 80mm outlet. Built in Miami from 304 stainless with a 1.5mm wall, it covers the F22 M240i through the X7 xDrive40i. For a B58 on factory software or a mild tune, this is the one to choose; the GESI Catted Downpipe for B58 costs more and suits owners who prefer the GESI converter.

Features

Active AFlow converter on an all-stainless substrate furnace brazed to the mantle
EPA registered, OBD2 compliant converter
Two-year guarantee against catalyst efficiency codes, with full replacement
Cast stainless upper V-band at the turbo
Stainless flex joint in the 3.5 inch section
Turbo flange gasket arrives fitted in the flange to protect it during installation

Specifications

Main piping diameter: 4.5 in
Flex section diameter: 3.5 in
Outlet diameter: 80mm
Wall thickness: 1.5mm
Converter diameter: 4.5 in
Catalyst cell density: 400 cpsi
Converter rating: Up to 800 hp
Temperature limit: 1500F

What’s Included

AFlow catted downpipe
Turbo flange gasket (pre-installed)

Applications

BMW 340i: F30 | 2016-2019 | 3.0L B58
BMW 440i: F32 / F33 / F36 | 2017-2020 | 3.0L B58
BMW 540i: G30 | 2017-2023 | 3.0L B58
BMW 640i Gran Turismo: G32 | 2018-2019 | 3.0L B58
BMW 740i: G11 | 2016-2022 | 3.0L B58
BMW M240i: F22 / F23 | 2017-2021 | 3.0L B58
BMW M340i: G20 | 2020-2024 | 3.0L B58
BMW M440i: G22 / G23 / G26 | 2021-2024 | 3.0L B58
BMW X3 M40i: G01 | 2018-2024 | 3.0L B58
BMW X5 xDrive40i: G05 | 2019-2023 | 3.0L B58
BMW X7 xDrive40i: G07 | 2019-2022 | 3.0L B58

Notes

The AFlow Catted Downpipe for B58 fits US-model vehicles; Active Autowerke cannot guarantee fitment on other market versions
On the G20 M340i and G22 M440i it pairs with the Mid-Pipe for G20 and Valved Axle-Back Exhaust for G20, and is sold in the AFlow Downpipe and Mid-Pipe Bundle and Full Exhaust Bundle with AFlow Downpipe
F30 340i and F3x 440i owners can add the Gen 2 B58 Valved Rear Exhaust
Warranty: 5 years or 50,000 miles on the shell, 2 years or 25,000 miles on the core, original purchaser only, void with more burble than stock

Frequently Asked Questions

Does the AFlow Catted Downpipe for B58 need a tune? No. Active Autowerke sells the AFlow Catted Downpipe for B58 BMW models as a no-tune part, and its two-year catalyst efficiency guarantee applies on factory software. A tune will extract more from the extra flow, but the downpipe does not need one.
Will it cause a check engine light? Active Autowerke guarantees the AFlow converter against catalyst efficiency codes for two years of ownership, with full replacement if one appears. The converter reaches working efficiency within 9 seconds of a cold start, so the rear oxygen sensor reads a working catalyst almost at once.
Does it fit 2025 and newer B58 models? No. This downpipe covers B58 vehicles through the 2024 model year. The updated B58 engine in 2025 and newer vehicles needs a different Active Autowerke downpipe, and the 2025 and newer M340i and M440i have their own version again, so check the model year before ordering.
Is the downpipe hard to install? No cutting or welding is needed. The downpipe seats on a cast stainless V-band at the turbo, the gasket arrives already fitted, and the 80mm outlet meets the factory exhaust. A lift makes the job easier, and the stock part can go back on later.
How does the AFlow version differ from the GESI version? The stainless pipework is identical. The AFlow version carries an Active AFlow converter rated for up to 800 horsepower plus a two-year code guarantee. The GESI version carries a GESI G-Sport converter rated from 500 to 850 horsepower and sells for more.

About Active Autowerke

Active Autowerke was founded in Miami, Florida in 1981 by brothers Mike and Karl Hugh as a BMW service shop, and turned to performance in late 1995 when Karl, a University of Miami engineering graduate, led its first M3 and 325i turbo kits. Supercharger kits for the E36, E46 and E9X followed, and its Signature Equal Length mid-pipe is protected by US Patent 11248511 and European and UK Patent 3882441.

Additional Information

The Bulletproof Automotive website contains many thousands of products purchased in multiple different currencies. All of the prices are entered manually and accurately at the time of entry. Due to the consistently fluctuating international exchange rates, at times prices may not be able to be honored at their original intended rate. We apologize for any inconvenience this may cause, unfortunately our website is unable to compensate dynamically for what can at times be volatile changes in the cost of items due to currency values fluctuating, changes in prices from suppliers, changes in shipping and import duties, and other factors. Rest assured that any order you place on line will be at zero risk to you in this area. If in the event your order cannot be fulfilled at the original intended website price we will offer you a 100% refund, no questions asked. We will continue to do our best to maintain updated prices and we will always continue to offer our price match guarantees as well to ensure our prices are always the best for you. In short, prices may change without notice. It is always advised to give us a call prior to placing your order online to confirm availability and to confirm current pricing.

Shipping Policy

Items that are in stock in the US, either at Bulletproof’s warehouse or at a supplier’s warehouse, are generally delivered within 7-10 days. Special order items from overseas take considerably longer. As a courtesy Bulletproof offers delivery estimates to our customers which take into consideration manufacturer availability and shipping schedule. These estimates represent our best guess based on previous orders from the manufacturer and do not in any way imply a guaranteed delivery window. Many manufacturers work in a “just in time” inventory system and often take 2-20+ weeks to produce an item once an order is submitted. All deliverable items are then sent to our Japanese warehouse. Bulletproof ships a minimum of one full ocean freight container every month from Japan, oftentimes more than one a month. Ocean freight takes an average of 4 weeks. Typically it breaks down to one week in Japan for paperwork and customs, two weeks by boat and one week in US customs/clearance. Due to the wide number of variables between manufacturer and shipping schedules, delivery estimates are simply just that – estimates. We attempt to estimate conservatively and we usually deliver faster than our estimates suggest. It is not Bulletproof’s policy to guarantee delivery time of any special order item, this is impossible for us to do. By ordering you acknowledge that there is no required delivery ETA and an order may not be canceled or altered due to manufacturing or shipping delays, all ETA’s are provided as a best guess only. Please review the full Terms & Conditions here.

BP Pricing Difference

We do pricing a little differently on our JDM brands and we believe in making things simple and clear. No hidden fees or surcharges. Every price you see includes the shipping cost to our office in Los Angeles, California and all the associated taxes/duties/fees for bringing the products into the US. The only shipping you ever pay is from our facility in the US to your location. Be wary of resellers that don’t include the cost of international shipping in their pricing on JDM parts. While we believe we’ll always have the lowest all-in price on JDM products, we offer a price match guarantee for all authentic parts purchased from authorized dealers as well. For many international customers, it’s much more affordable to ship from the USA than from Japan directly, as the air freight and ocean freight costs are typically much less. However, for customers looking to ship directly from Japan outside of North America, or domestically in Japan, we can provide pricing specifically for that scenario. Please do not hesitate to contact us with any pricing questions or concerns. Please email us at sales@bulletproofautomotive.com with any inquiries.

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Active Autowerke AFlow Catted Downpipe for B58 BMW 2 to 7 Series, X3, X5 and X7 (2024 and Older)

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Active Autowerke AFlow Catted Downpipe for B58 BMW 2 to 7 Series, X3, X5 and X7 (2024 and Older)

Features

Specifications

What’s Included

Applications

Notes

Frequently Asked Questions

About Active Autowerke

Reviews