Milltek Cat Back Exhaust - BMW F8X M3/M4 (ECE approved)

QT Parts is a Finnish online store.

Our warehouse is located in Nokia, Finland.

You can collect your order directly from us if needed. Simply select “Pickup” at checkout.

Pay securely with multiple payment methods, including invoice and installment plans through Klarna.

The delivery time for products in stock is 1-5 business days. We ship worldwide.

If the product is not in stock and it is a pre order product, the average delivery time is 5-21 business days. If the product has a longer delivery time than previously announced, we will be in touch. International orders may be subject to VAT, import duties, and customs fees upon arrival in the destination country.

Terms for product returns:

• You must return the ordered products within 14 days of receiving
• The products must be unused and without damages
• Commission fee for handling returns is 21,90€
• For product returns, the customer is in charge of the return costs. Only door to door service (Express)
• Shipping costs are not refunded

For international orders sales are final and non-refundable. Once an order is placed, it cannot be canceled or returned. By placing an order, you acknowledge and agree to these terms.

Return address: QT Parts, Vasarakatu 8B, 37150 Nokia, Finland.

Pre order / made-to-order products

If the product you have ordered is a pre order or made-to-order item, it is not subject to the 14-day right of withdrawal or return under consumer protection laws, as the product is manufactured or sourced specifically based on the customer’s individual order.

If you wish to cancel your order before receiving the product, we will refund 50% of the total order amount.

This condition applies to the following product categories:

• Suspension
• Engine Tuning
• Engine Parts
• Exhaust Systems
• Fueling
• Turbochargers/superchargers
• Drivetrain
• ECE-approved Downpipes

All of the above products are manufactured or sourced individually based on the customer’s order, and therefore cannot be returned after delivery, unless the product has a manufacturing or material defect.

In the event of such a defect, the standard liability for defects as provided by consumer protection legislation shall apply.

The Milltek Sport Cat Back exhaust system is designed to deliver a more powerful, richer and motorsport-inspired sound to the BMW F8X generation M3 and M4 models. Since the 2014-2018 non-OPF models do not include a particulate filter, the Cat Back system is able to produce a fuller, freer-flowing sound signature that makes the S55 engine’s character even more lively and dynamic.

The system delivers a sound that perfectly matches the aggressive aesthetics and performance of the F8X models: a deeper bass range, a sharper throttle response sound and a sporty high-rev nuance without excessive hum when driving on the road.

Note! The exhaust is only ECE-approved in the Road version. Other options are without ECE approval.

A more sporty sound

Milltek's Cat Back kit replaces the rear end of the exhaust system:

• Deep and clear idle sound

• Lively and dynamically growing sound with the revs

• Motorsport-inspired exhaust sound without artificial resonance

• Balanced noise level suitable for both street and sports use

This system is designed to produce a clean, crisp sound profile that matches the character of the S55 engine.

Easy bolt-on installation

The Milltek Cat Back is a direct replacement for the car's original rear pipes:

• Fits the car's original mounting points

• Completely bolt-on, no structural modifications required to the car

• Full compatibility with the original valve control (depending on model)

• Precision fit and OEM-level finish

Premium construction: 304L grade stainless steel

Milltek uses only high quality 304L Aircraft Grade stainless steel, which offers:

• Very good corrosion resistance

• Long service life even in hard sporty driving

• Perfect flow efficiency

• For a professional weld finish and clean appearance

The material is of the same standard as components used in the aerospace industry.

Output and configuration options

Several outlet styles available, including:

• Polished stainless steel

• Black ceramics

• Titanium

• Carbon fiber coating

These can be used to customize the car's appearance to suit the driver's own taste.

Compatibility: BMW F8X M3/M4 (non-OPF/GPF)

This Cat Back system fits the following models from 2014-2018:

• BMW M3 F80

• BMW M3 Competition F80

• BMW M4 Coupe F82

• BMW M4 Convertible F83

• BMW M4 Competition (F82/F83)

All versions: rear-wheel drive, DCT, manual. Not for OPF models. For exhaust suitable for models with OPF, click HERE