BMW 1 Series 128ti 5 Door (F40 OPF/GPF Equipped) Exhaust System

Experience noticeable power gains, an awesome sound, and aggressive yet discrete styling. Manufactured since 1983 in the UK from premium T304L aircraft-grade stainless steel, chosen for its superior quality and anti-magnetic properties, every system ensures ultimate performance and a sharper throttle response through features like mandrel-bent, full-flow pipework.

Milltek’s performance stainless steel exhausts offer genuine power gains, an exhilarating sound, and a significant improvement in driveability and throttle response.

Key Features & Advantages:

Premium Material: Manufactured from anti-magnetic, non-discoloring Type T304L aircraft-grade stainless steel for superior quality throughout all pipework and silencers.
Optimised Flow: Increased bore size and mandrel-bent, full-flow pipework ensure ultimate performance without sacrificing mid-range torque.
Proven Expertise: Over 40 years of continuous development, with all systems designed, developed, and manufactured in the UK since 1983.
Weight Saving: Substantial weight reduction over original equipment.
Comprehensive Range: Systems include cat-back, GPF/OPF-back, sports cats, de-cats, and more.

Need fitting guidance for your exhaust system, call +44 (0)1789 774444 or contact us directly.

Find your next BMW 1 Series 128ti 5 Door (F40 OPF/GPF Equipped) Exhaust System

SKU	Product Type	Tip Style	Additional Options	Notes	Pipe MM	Pipe Inches	EC Approved	Race System
MILLTEK1170-A	Particulate Filter-back	Quad 100mm GT100	Maxton x Milltek – OPF/GPF Back System – Quad GT-100 Brushed Titanium Trims – ECE Approved	MUST BE Fitted with Maxton Diffuser	76.2	3.0	Y	X
MILLTEK1170-B	Particulate Filter-back	100mm GT100	Maxton x Milltek – OPF/GPF Back System – Quad GT-100 Burnt/Blue Titanium Trims – ECE Approved	MUST BE Fitted with Maxton Diffuser	76.2	3.0	Y	X
MILLTEK1170-C	Particulate Filter-back	Quad 100mm GT100B	Maxton x Milltek – OPF/GPF Back System – Quad GT-100 Cerkote Black Trims – ECE Approved	MUST BE Fitted with Maxton Diffuser	76.2	3.0	Y	X
MILLTEK1170-D	Particulate Filter-back	Quad 100mm GT100	Maxton x Milltek – OPF/GPF Back System – Quad GT-100 Polished Trims – ECE Approved	MUST BE Fitted with Maxton Diffuser	76.2	3.0	Y	X
MILLTEK1170-E	Particulate Filter-back	115mm GT115	OPF/GPF Back System – GT-115 Brushed Titanium Trims – ECE Approved		76.2	3.0	Y	X
MILLTEK1170-F	Particulate Filter-back	115mm GT115	OPF/GPF Back System – GT-115 Burnt Titanium Trims – ECE Approved		76.2	3.0	Y	X
MILLTEK1170-G	Particulate Filter-back	115mm GT115	OPF/GPF Back System – GT-115 Cerakote Black Trims – ECE Approved		76.2	3.0	Y	X
MILLTEK1170-H	Particulate Filter-back	115mm GT115	OPF/GPF Back System – GT-115 Polished Trims – ECE Approved		76.2	3.0	Y	X
MILLTEK1170-I	Particulate Filter-back	115mm JET-115	OPF/GPF Back System – JET-115 Carbon Trims – ECE Approved		76.2	3.0	Y	X
MILLTEK1170-J	Additional parts		Maxton Diffuser for Quad Outlet System (M2 Style) – Gloss				X	X
MILLTEK1170-K	GPF/OPF Bypass		Fits to the Milltek Sport OPF/GPF Back System Only	Requires Stage 2 ECU Remap or OPF/GPF Bypass Module (Available from www.leib-engineering.de)	76.2	3.0	X	Y
MILLTEK1170-L	GPF/OPF Bypass		Fits to the OE OPF/GPF Back System Only MSBM393	Requires Stage 2 ECU Remap or OPF/GPF Bypass Module (Available from www.leib-engineering.de)	76.2	3.0	X	Y

Additional information

Shipping & Delivery

Items are shipped from the United Kingdom, unless otherwise stated on the product listing.

We typically expect product delivery times to be up to 14 days but it is subject to stock availability, lead time can take up to 4 weeks.

For customers outside the UK, import duties and local taxes are not included.

If applicable, the courier will contact you directly to collect any duties or taxes prior to delivery. These charges are determined by local authorities and cannot be avoided or reduced.

Authorised Dealer & Warranty Assurance

VIEZU Technologies Ltd is an authorised Milltek dealer.
All Milltek exhaust systems supplied by us are sourced through official UK distribution channels and are eligible for the manufacturers warranty, subject to Milltek's standard terms and conditions.

In some cases, Milltek products may be purchased via the Paramount Performance online store. Where this applies:

The product is still supplied via VIEZU Technologies Ltd as an authorised Milltek dealer, ensuring full warranty eligibility.
Warranty support is provided through the authorised supply chain in line with Milltek requirements.
Proof of purchase from Paramount Performance, together with product identification details, will be accepted for warranty purposes.

This structure ensures customers receive the same level of manufacturer-backed support regardless of which of our websites the purchase is completed on.

Milltek Warranty Information

Milltek exhaust systems are supplied with a manufacturer-backed warranty when purchased through an authorised dealer.

Warranty Eligibility

To qualify for warranty coverage:

The warranty applies to the original purchaser only.
Proof of purchase is required and may include part numbers or batch identification.
The exhaust system must be installed correctly by a competent professional and must not be modified or altered.
Warranty claims must be initiated through the supplying dealer.

Standard Warranty Coverage

Warranty coverage varies by product type:

Hi-Flow Catalysts and Downpipes: 2 years or 80,000 km (whichever occurs first) against manufacturing defects.
Valved Exhaust Components (including electronic systems): 2 years or 80,000 km warranty.
All Other Milltek Exhaust Components: Lifetime warranty against manufacturing defects under normal road use.

Important Warranty Conditions

The warranty does not cover faults or damage caused by:

Incorrect or improper installation
Modifications after manufacture
Motorsport or track use
Vehicle-related issues such as worn engine mounts or excessive drivetrain movement
Use outside the intended vehicle application
Abuse, impact damage, excessive vibration, or exhaust backfire damage

Please note:

Warranty coverage applies to the product only.
Labour, removal, refitting, recovery, transport, and associated costs are not covered.

Fitment & Compatibility

Milltek exhaust systems are vehicle-specific. Customers are responsible for confirming correct fitment for their exact vehicle make, model, engine, and year prior to purchase. If you are unsure, please contact us before ordering for assistance.