Milltek Downpipe & Sports Cat for Ford Mustang 2.3 EcoBoost (S550 Fastback) (2015-2018) – Improved Flow, Sports Catalyst
This is Milltek's large-bore downpipe with hi-flow sports cat for the Ford Mustang 2.3 EcoBoost (S650 Fastback). It replaces the restrictive factory downpipe with a larger-bore pipe fitted with a high-flow sports catalyst in place of the standard unit, using a less dense substrate that flows significantly better than the factory cat while still treating the exhaust gases passing through it. It's offered in versions to suit the factory or a Milltek system, so you can pick the setup that suits how the car's used.
It sits between a stock downpipe and a full de-cat: a genuine flow gain suited to a Stage 1 or Stage 2 remap, without giving up the catalyst entirely the way a de-cat pipe does.
In the UK, a replacement catalyst on a car first registered from 1 March 2001 needs ECE R103 type-approval to be road legal, so check the EC Approved line in the specification for the version you choose.
Specifications
-
System Type: Large Bore Downpipe and Hi-Flow Sports Cat
-
Pipe Diameter: 70mm (2.76")
-
EC Approved: No
-
Race System: Yes
Key Features
- Made from T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration
- Mandrel-bent pipework keeps a constant diameter through every bend for unrestricted flow
- 70mm (2.76") pipework
- High-flow sports catalyst flows better than the dense factory unit while still treating exhaust gases
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- Ford Mustang 2.3 EcoBoost (S550 Fastback) (2015-2018)
- Ford Mustang 2.3 EcoBoost (S650 Fastback) (2024 onwards)
Not suitable for: any model, engine or body style not listed above. Check your car before ordering.
Installation
Some versions: For Fitment to Milltek Sport Cat Back Systems Only. Stage 2 ECU Remap Required. Some versions: For Fitment to OE System Only. Stage 2 ECU Remap Required. This work involves removing parts close to the turbo and engine, so we recommend fitting by a specialist with a ramp and suitable software support.
Upgrade Further
Also available from Milltek for this car: Milltek Cat-back Exhaust Ford Mustang 2.3 EcoBoost S550 Fastback 15-18.
Will it fit the Ford Mustang 2.3 EcoBoost (S650 Fastback)?
Yes. Milltek lists this part for the Ford Mustang 2.3 EcoBoost (S650 Fastback) as well as the other models in the fitment list above.
Is it road legal?
Milltek lists this as a race part without EC approval, so it is intended for off-road and competition use.
Do I need a remap?
Yes. Milltek notes: "Fits Milltek Cat Back Only, Stage 2 Remap Required". Without suitable software the engine management is likely to log faults.
Can I use it with my standard exhaust?
It depends on the version. Some are made for the factory (OE) system and others for the Milltek cat-back, so check the notes for the option you choose.
How is a sports cat different from a de-cat?
A sports cat still contains a catalyst, just a less dense one that flows better than the factory unit. A de-cat removes the catalyst completely.
What is it made from?
T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration better than lower grades.
Is there a warranty?
Yes. Milltek products are covered against defects in materials and workmanship. Contact us with your order number if you have a problem.
