BMW M54 2.5L/3.0L Catless Exhaust Headers for E46 325/330, E39 525i/530i & E85 Z4

SKU: XKV11153
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Fitment & Specs
Selected BMW M54 applications: E46 325/330, 2001-2003 E39 525i/530i, and 2003-2005 E85 Z4 2.5i/3.0i. Excludes 323i/328i/528i M52/M52TU applications.
2" Outlet
T304 Stainless Steel · Professional Installation Recommended
Before You Buy: Off-road/racing use only · Professional install recommended · Vehicle / Setup Dependent
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Description
BMW M54 · CATLESS EXHAUST HEADERS

Catless T304 Stainless Headers for BMW M54 2.5L & 3.0L

This performance exhaust header set is designed for selected BMW applications equipped with the M54B25 2.5L or M54B30 3.0L inline-six engine. Core applications include selected E46 325/330 models, E39 525i/530i, and E85 Z4 2.5i/3.0i models.

The factory manifold and integrated catalytic-converter section is replaced with a catalyst-free tubular header configuration using T304 stainless steel, mandrel-bent primary tubes, CNC-machined flanges and TIG/MIG-welded construction.

Engine Family BMW M54
Engine M54B25 / M54B30
Product Type Catless Header Set
Material T304 Stainless Steel

Know What This Header Set Fits

This is an M54 2.5L / 3.0L header set. It should not be treated as a universal E46, E39 or BMW inline-six header.

The earlier E46 323i/328i and E39 528i use a different M52/M52TU header family. Those 2.8L applications are not part of the current XKV11153 fitment.

BMW M3/S54 and later E90/N52 applications are also outside the current fitment.

Key Features

  • T304 stainless steel tubular header construction
  • 1.75-inch primary tubes
  • 2-inch outlets
  • 7/16-inch cylinder-head flange thickness
  • 3/8-inch outlet flange thickness
  • Mandrel-bent tubing for smooth exhaust routing
  • CNC-machined flanges
  • TIG/MIG-welded construction
  • Four O2 sensor bungs
  • No integrated catalytic converters

Vehicle Fitment

Vehicle Chassis / Years Engine
BMW 325i / 325Ci / 325xi Selected E46 applications M54B25 2.5L
BMW 330i / 330Ci / 330xi Selected E46 applications M54B30 3.0L
BMW 525i E39 · 2001–2003 M54B25 2.5L
BMW 530i E39 · 2001–2003 M54B30 3.0L
BMW Z4 2.5i E85 · 2003–2005 M54B25 2.5L
BMW Z4 3.0i E85 · 2003–2005 M54B30 3.0L
E46 fitment note: E46 compatibility is model-year and body-style specific rather than universal. Current XKV/supplier fitment data contains specific exclusions within the model range, including 2002 325Ci/330Ci, and identifies 2006 fitment as body-style sensitive. Some xDrive/xi year coverage is also application-specific. Please verify the exact model, model year, chassis, engine and drivetrain before ordering.

Not Designed For

Do not use this listing for: BMW 323i, 328i or 528i M52/M52TU 2.8L applications, BMW M3/S54 applications, or standard E90/N52 325i/330i applications. Additional BMW chassis using an M54 engine are not automatically confirmed unless specifically listed above.

Before Installation

  • Confirm that the vehicle uses an M54B25 2.5L or M54B30 3.0L engine.
  • Verify the exact chassis, model year, body style and drivetrain.
  • Compare the outlet flange and downstream exhaust connection before installation.
  • Inspect O2 sensor routing and available clearance before final tightening.
  • Installation instructions are not included.
  • Professional installation is recommended.

Catless / Emissions Notice

This is a catless header set and does not include integrated catalytic converters.

Removing or replacing factory emissions-related components may affect emissions compliance, O2-sensor monitoring and diagnostic fault codes depending on the vehicle and setup. Tuning or other supporting changes may be required in some applications.

This product is intended for off-road, racing or closed-course use where emissions laws apply. Verify local regulations and installation requirements before purchase.

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.

What Does an Exhaust Header Actually Do?

The exhaust header is the first section of the exhaust system and mounts directly to the engine. Its role is to collect exhaust gases from each cylinder and route them into the rest of the exhaust system.

Compared to many factory manifolds, header designs often focus on smoother internal flow and more uniform exhaust routing before gases move downstream.

What You May Notice After Installation

Smoother exhaust flow as engine speed increases

More consistent engine behavior across the RPM range

Improved exhaust routing when paired with other intake or exhaust components

Changes in exhaust tone, depending on system configuration

When This Type of Upgrade Is Typically Considered

Addressing airflow limitations in the factory exhaust manifold

Planning coordinated intake or exhaust system updates

Replacing aging or restrictive original components

Build a balanced, performance-focused setup

Factory Manifold vs. Performance Header

Factory Exhaust Manifold

Designed to meet packaging, cost, and emissions requirements
Prioritizes durability and compliance across broad use cases

Performance Exhaust Header

Designed with exhaust flow characteristics in mind
Built for higher exhaust temperatures and specific vehicle platforms
Commonly used as part of an exhaust system configuration

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.

Frequently Asked Questions

What do exhaust headers do? +

Exhaust headers help route exhaust gases away from the engine through individual tubes and collector-style routing. Actual results depend on the vehicle, engine condition, exhaust system, installation quality, and supporting components.

What's the difference between headers and factory manifolds? +

Factory manifolds are typically designed around packaging, durability, emissions requirements, and production cost. Headers or manifold-related exhaust upgrades may use different tube routing, flange designs, or connection layouts depending on the application.

Will headers increase horsepower? +

Headers may support improved exhaust flow where the product is compatible, but horsepower and torque changes are not guaranteed. Results vary by engine setup, tuning, exhaust configuration, vehicle condition, installation, and supporting modifications.

Do headers make the vehicle louder? +

Headers and related exhaust parts can change exhaust tone and may increase sound depending on the rest of the exhaust system. Final sound level depends on the engine, mufflers, catalytic converters, pipe routing, and complete exhaust setup.

Do I need tuning after installing headers? +

Tuning requirements depend on the vehicle, engine management system, O2 sensor setup, emissions equipment, and supporting modifications. Some installations may not require tuning, while modified builds may require professional inspection, calibration, or tuning to support proper drivability.

Are header products street legal? +

Header and exhaust products may be intended for off-road or racing use where emissions laws apply. They are not represented as street legal, emissions-compliant, or CARB-compliant for public road use unless a valid exemption is explicitly stated. Always check local regulations before purchase and installation.

Can I use headers with a stock exhaust system? +

Compatibility with a stock exhaust system depends on the vehicle and existing exhaust configuration. Some vehicles may require additional hardware, gaskets, connectors, adjustment, or fabrication to complete installation.

Are headers hard to install? +

Installation difficulty varies by vehicle. Tight engine bays, old hardware, rust, engine swaps, modified exhaust systems, sensor placement, and clearance around surrounding components can increase installation complexity. Professional installation is recommended.

Will headers affect reliability? +

Reliability depends on fitment accuracy, installation quality, vehicle condition, heat management, gasket sealing, fastener condition, sensor placement, and supporting components. Proper inspection and installation are important.