BMW X4 2021

Service Completed: OPF Delete, Decat & Mid-Section Upgrade

At MIJ Exhaust Ltd, we recently carried out a full exhaust transformation on this BMW X4 M Competition (2021), built to unlock both performance and sound from this high-powered platform.

The vehicle came in for an OPF delete, decat, and a custom mandrel-bent mid-section upgrade. By removing the restrictive factory components and improving flow throughout the system, this setup delivers a much sharper throttle response and a significantly more aggressive, free-flowing exhaust note.

The mandrel-bent pipework ensures smooth airflow with minimal restriction, helping the engine perform more efficiently while producing a deeper, more pronounced tone under acceleration—bringing the X4 M Competition to life.

As with all of our work, the system was hand-fabricated in-house using premium T304 stainless steel and fully TIG welded, ensuring durability, precision fitment, and a clean, high-quality finish.

This project didn’t stop at a one-off build—following the success of this setup, the client requested that we develop these systems for mass production. That’s exactly what we delivered, creating a repeatable solution without compromising on quality or performance.

Be sure to check out the video to see the work carried out and hear the incredible sound this upgrade produces.
https://www.instagram.com/p/DXAQg7oiAtI/

Why Choose a Custom MIJ Exhaust?

No two vehicles—and no two customers—are alike. That’s why every exhaust system we build is custom-made on the vehicle for the perfect fit, tone, and performance.

Whether you’re after:

A sportier, more aggressive sound,

A performance-focused setup, or

A refined, OEM-style tone,

—we tailor the design specifically to your goals.

More Than Just Custom Builds

We provide all types of exhaust services, including:

Exhaust repairs and leak fixes

Section replacements

Welding cracks and fault correction

Tailpipe upgrades and cosmetic enhancements

Small adjustments and one-off jobs