Do I need a tune for the GESI Catted Downpipe for B58N?

No. Active Autowerke states that the GESI Catted Downpipe for B58N BMW models runs correctly without a performance tune. The 1,000 horsepower converter rating means a tune, or a more serious build, can follow later without the downpipe ever needing to be changed.

Is the GESI version worth the extra over AFlow?

No, not for most owners. The pipework is identical, and the GESI unit is rated to 1,000 horsepower against 950 for the AFlow converter, so on a stock or mildly tuned B58N the AFlow version does the same job for less. The GESI suits a heavily built engine.

Does this fit a 2025 M340i?

No. Active Autowerke excludes the 2025 and newer M340i and M440i from this downpipe because their factory downpipe is built differently. Those two models take their own Active Autowerke GESI downpipe, designed specifically for the G20 and G22 cars and sold separately.

Will the GESI converter cause a check engine light?

Active Autowerke states that it will not set a catalyst efficiency code. The converter uses a 400 cell substrate with GESI precious metal loading and reaches working efficiency within 9 seconds of a cold start, which is what keeps the rear oxygen sensor content.

What vehicles does it fit?

Active Autowerke lists the 2025 and newer 540i, 640i, 740i, X3, X5 xDrive40i and X7 xDrive40i with the third-generation B58 engine, and confirms fitment on US-model vehicles only. Supply the VIN with the order if there is any doubt about which engine version is fitted.

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Description

Active Autowerke GESI Catted Downpipe for B58N BMW 5 to 7 Series, X3, X5 and X7 (2025 and Newer)

Active Autowerke’s GESI Catted Downpipe for B58N BMW 5 to 7 Series, X3, X5 and X7 fits the 2025 and newer third-generation inline six with a 5 inch, 1.5mm wall stainless downpipe built around a GESI G-Sport ultra high output converter rated for up to 1,000 horsepower. A stainless flex joint and a step to the stock 80mm outlet let it bolt to the factory exhaust behind it. The rating sits only 50 horsepower above the AFlow version, so the GESI unit is for owners building a heavily modified B58N or who specifically want a GESI converter; everyone else should look at the AFlow Catted Downpipe for B58N.

Features

GESI G-Sport converter with a furnace-brazed 304 stainless substrate and proprietary precious metal loading
EPA registered and OBD2 compliant GESI converter
Designed to avoid catalyst efficiency check engine lights
Cast stainless V-band flange at the turbo
Comes with a turbo flange gasket
Hand-built in Miami, Florida from TIG welded 304 stainless steel

Specifications

Main piping diameter: 5 in
Outlet diameter: 80mm
Wall thickness: 1.5mm
Converter diameter: 5 in
Catalyst cell density: 400 cpsi
Converter rating: Up to 1,000 hp
Temperature limit: 1500F

What’s Included

GESI catted downpipe
Turbo flange gasket

Applications

BMW 540i: G60 | 2025-present | 3.0L B58N
BMW 640i: 2025-present | 3.0L B58N
BMW 740i: G70 | 2025-present | 3.0L B58N
BMW X3: G45 | 2025-present | 3.0L B58N
BMW X5 xDrive40i: G05 | 2025-present | 3.0L B58N
BMW X7 xDrive40i: G07 | 2025-present | 3.0L B58N

Notes

The GESI Catted Downpipe for B58N is not for the 2025 and newer M340i or M440i; those cars use the GESI Catted Downpipe for G20
Vehicles with the earlier B58, through 2024, take the GESI Catted Downpipe for B58
Active Autowerke confirms fitment for US-model vehicles only
The shell and tube ends carry a 5 year or 50,000 mile warranty and the catalytic core 2 years or 25,000 miles, for the original purchaser. Tuning for more burble than stock voids it.

Frequently Asked Questions

Do I need a tune for the GESI Catted Downpipe for B58N? No. Active Autowerke states that the GESI Catted Downpipe for B58N BMW models runs correctly without a performance tune. The 1,000 horsepower converter rating means a tune, or a more serious build, can follow later without the downpipe ever needing to be changed.
Is the GESI version worth the extra over AFlow? No, not for most owners. The pipework is identical, and the GESI unit is rated to 1,000 horsepower against 950 for the AFlow converter, so on a stock or mildly tuned B58N the AFlow version does the same job for less. The GESI suits a heavily built engine.
Does this fit a 2025 M340i? No. Active Autowerke excludes the 2025 and newer M340i and M440i from this downpipe because their factory downpipe is built differently. Those two models take their own Active Autowerke GESI downpipe, designed specifically for the G20 and G22 cars and sold separately.
Will the GESI converter cause a check engine light? Active Autowerke states that it will not set a catalyst efficiency code. The converter uses a 400 cell substrate with GESI precious metal loading and reaches working efficiency within 9 seconds of a cold start, which is what keeps the rear oxygen sensor content.
What vehicles does it fit? Active Autowerke lists the 2025 and newer 540i, 640i, 740i, X3, X5 xDrive40i and X7 xDrive40i with the third-generation B58 engine, and confirms fitment on US-model vehicles only. Supply the VIN with the order if there is any doubt about which engine version is fitted.

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 GESI Catted Downpipe for B58N BMW 5 to 7 Series, X3, X5 and X7 (2025 and Newer)

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Active Autowerke GESI Catted Downpipe for B58N BMW 5 to 7 Series, X3, X5 and X7 (2025 and Newer)

Features

Specifications

What’s Included

Applications

Notes

Frequently Asked Questions

About Active Autowerke

Reviews