BMW N55 4" Catless Downpipe for M135i F20/F21, M235i F22/F23, 435i F32/F33 & 2016-2018 F87 M2

SKU: XKV21065
Availability : In Stock Pre order Out of stock
$176.56 $133.80 SAVE $42.76
Fitment & Specs
2013-15 M135i F20/F21, 2014-16 M235i F22/F23, 2014-16 435i/435i xDrive F32/F33 & 2016-18 N55 F87 M2
T304 Stainless Steel · Vehicle-Specific Replacement / Fitment Verification Required
Before You Buy: Off-road/racing use only · Professional install recommended
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Description
BMW N55 4 Inch Catless Downpipe

4" Catless Downpipe for Selected BMW N55 F-Series Applications

This vehicle-specific catless downpipe is designed for selected BMW N55 3.0L single-turbo F-Series applications, including M135i, M235i, 435i and N55-powered F87 M2 models listed in the fitment table below.

Constructed from T304 stainless steel with 4-inch mandrel-bent piping, a precision CNC-machined turbocharger V-band flange and TIG-welded construction.

Product Type Catless Downpipe
Pipe Diameter 4 Inch
Material T304 Stainless Steel

Key Product Details

  • Designed for selected BMW N55 3.0L single-turbo F-Series applications
  • 4-inch catless downpipe configuration
  • T304 stainless steel construction
  • Precision CNC-machined turbocharger V-band flange
  • Mandrel-bent 4-inch piping
  • TIG-welded construction
  • Package includes one downpipe

Vehicle Fitment

Fitment is application-specific. Confirm the exact model, model year, chassis and N55 engine before ordering.

Vehicle Chassis Year Engine
BMW M135i F20 / F21 2013–2015 N55 3.0L Turbo
BMW M235i F22 / F23 2014–2016 N55 3.0L Turbo
BMW 435i / 435i xDrive F32 / F33 2014–2016 N55 3.0L Turbo
BMW M2 F87 2016–2018 N55 3.0L Turbo
Important Fitment Note: BMW N55 applications do not all use the same downpipe configuration. Compatibility should not be determined by the N55 engine name alone. Verify the exact chassis and physical exhaust connections before purchase.
M2 Fitment: This listing is for N55-powered F87 M2 applications only. It is not intended for later S55-powered M2 Competition / M2 CS applications or G87 M2 models.

Before You Buy

  • Confirm your exact BMW model and model year
  • Confirm the chassis code shown in the fitment table
  • Confirm the vehicle is equipped with the compatible N55 3.0L turbo engine
  • Compare the turbo-side and downstream exhaust connections with the product photos
  • Verify sensor configuration and available installation clearance before installation

Package Includes

  • 1 × 4" catless downpipe

Installation

Professional installation is recommended. Inspect the vehicle and compare the original downpipe connections with the replacement part before final installation. Vehicle-specific installation work or replacement hardware may be required depending on the condition and configuration of the original exhaust components.

Emissions & Vehicle Use

This is a catless exhaust component that replaces a factory catalytic downpipe section where compatible. Emissions, inspection and road-use requirements vary by jurisdiction. Verify all applicable requirements before purchase, installation and vehicle use.

Shipping & Return

SHIPPING & DELIVERY
Fast Processing & Reliable Transit

  • Processing: Orders are processed and shipped from the nearest available warehouse within 1 business day after payment.
  • Delivery: Estimated delivery time is approximately 3–4 business days after shipment.
  • Shipping - Free shipping on all orders within the contiguous 48 U.S. states.

RETURNS & EXCHANGES
30-Day Hassle-Free Policy

  • Return Window: We offer a 30-day return policy from the date of delivery.
  • Item Condition: Returned items should be unused, uninstalled, and in their original packaging when possible.
  • Return Process: To initiate a return or exchange, please contact our customer service team first to receive authorization and instructions.

WARRANTY
2-Year Limited Replacement Warranty

  • Duration: All products are backed by a 2-year limited warranty.
  • Coverage: This warranty covers manufacturing defects and product failures under normal use, and provides a replacement for qualified cases (repairs are not performed).

CUSTOMER SUPPORT
We’re Here to Help – Contact Us First

  • Priority Contact: For any order-related issues—including returns, warranty claims, or general inquiries—please contact us first before taking further action. We are committed to resolving your concern promptly.
  • Feedback Notice: If you are unsatisfied, we kindly ask that you allow us an opportunity to address the issue before leaving neutral or negative feedback.
  • Email Support: You can reach us at support@XKVracing.com.

Downpipe Buying Guide

A Key Section in a Turbocharged Exhaust System

The downpipe connects directly to the turbocharger and routes exhaust gases into the rest of the exhaust system. It is one of the first exhaust components downstream of the turbo.

Because of its position, the design of the downpipe influences how exhaust gases move away from the turbo and into the remaining exhaust path.

What Drivers May Observe

More consistent exhaust flow downstream of the turbocharger

Reduced restriction compared to some factory exhaust layouts

Smoother boost delivery under certain operating conditions

Changes in exhaust tone, depending on system setup

Catted vs Catless

Catted Downpipe

Includes a catalytic converter designed for specific applications
Used where emissions considerations or regulations apply
Often selected for vehicles intended for street use, where permitted

Catless Downpipe

Does not include a catalytic converter
Typically intended for off-road, competition, or export use
Used in applications where different regulatory standards apply

Is a Downpipe Right for Your Build?

Own a turbocharged vehicle

Are upgrading intake, intercooler, or exhaust components

Want improved exhaust efficiency and response

Are building a balanced street or track setup

FAST SHIPPING

Ships within 1 business day after payment
3–4 business day delivery

Secure and Reliable Checkout

Secure checkout with major payment options

LOCAL WAREHOUSE

Orders ship from U.S. warehouses when available

Easy Returns and Exchanges

30-day returns for eligible unused items

Parts Warranty

Warranty support for qualified manufacturing defects

Important Notice

Products on this site are intended for off-road, racing, or closed-course use where emissions laws apply. They are not represented as street legal, emissions-compliant, or legal for use on public roads unless explicitly stated.

Some products may remove, replace, relocate, disable, or alter emissions-related components, including but not limited to catalytic converters, EGR, DPF, SCR, DOC, O2 sensors, or related factory systems. Compatible tuning, calibration, or supporting modifications may be required to avoid engine codes or drivability issues.

Professional installation is recommended. Buyers are responsible for verifying product compatibility, local regulations, emissions requirements, and any required tuning or supporting modifications before purchase and installation.

Performance gains, sound changes, airflow improvements, temperature changes, fuel economy changes, fitment, and drivability results may vary. No specific performance gains are guaranteed.

Downpipe FAQs

What is a downpipe? +

A downpipe is the exhaust section that connects to the turbocharger and routes exhaust gases toward the rest of the exhaust system. Depending on the vehicle and product design, an upgraded downpipe may help reduce exhaust restriction and support improved turbo response when paired with the right setup.

What's the difference between catted and catless downpipes? +

A catted downpipe includes a catalytic converter, while a catless or racing downpipe does not include one and may alter or remove emissions-related equipment. Catless or racing downpipes are generally intended for off-road, racing, or closed-course use where emissions laws apply. Always check the product details and local regulations before purchase.

Will a downpipe increase horsepower? +

A downpipe may support improved exhaust flow and power potential when combined with proper tuning and supporting modifications. Horsepower and torque gains are not guaranteed and will vary depending on the vehicle, engine condition, tune, fuel, turbo setup, and overall exhaust system.

Do downpipes make the vehicle louder? +

A downpipe can change exhaust tone and may increase turbo or exhaust sound depending on the vehicle, whether the downpipe is catted or catless, and the rest of the exhaust system. Final sound level varies by setup.

Do I need tuning after installing a downpipe? +

Tuning requirements depend on the vehicle, downpipe design, emissions equipment, O2 sensor setup, and supporting modifications. Some applications may require compatible tuning or calibration to support drivability and reduce the chance of warning lights or engine codes.

Will a downpipe trigger a check engine light? +

It may, depending on the vehicle, catalytic converter configuration, O2 sensor location, and ECU calibration. Catless or racing downpipes are more likely to require supporting calibration or sensor-related solutions. Always verify the product notes and tuning requirements before installation.

Are downpipes street legal? +

Street legality depends on the downpipe design, emissions equipment, vehicle application, and local regulations. Catless, racing, or emissions-altering downpipes are generally intended for off-road, racing, or closed-course use where emissions laws apply and are not represented as street legal unless explicitly stated.

Can I use a downpipe with my stock exhaust system? +

Compatibility with a stock exhaust system depends on the vehicle and the specific downpipe design. Some downpipes are designed to connect to factory-style exhaust sections, while others may require compatible aftermarket exhaust parts, adapters, clamps, gaskets, or fabrication. Always check the product fitment and installation notes before ordering.

Are downpipes hard to install? +

Installation difficulty varies by vehicle. Some applications require tight access around the turbocharger, O2 sensors, heat shields, transmission area, or underbody. Rusted factory hardware and limited clearance can also increase installation difficulty. Professional installation is recommended.

Will a downpipe affect reliability? +

Reliability depends on product fitment, installation quality, tuning or calibration, heat management, sensor placement, gasket sealing, fastener condition, and the vehicle’s overall condition. Incorrect installation or mismatched tuning may cause drivability issues.

What should I verify before buying a downpipe? +

Verify your year, make, model, engine, turbo setup, emissions configuration, catalytic converter requirements, O2 sensor layout, flange or clamp connection, exhaust compatibility, and any tuning or calibration needs before purchase.