Milltek Downpipe & De-cat for Audi RS3 Saloon/Sedan 400PS (8V MQB) - OPF/GPF Models (2019 onwards) – Maximum Flow, Motorsport Use
This is Milltek's large-bore downpipe and de-cat for the Audi RS3 Sportback 400PS (8V MQB - Facelift Only) - OPF/GPF Models. It replaces the factory downpipe with a larger-bore pipe and removes the catalytic converter entirely, clearing the single most restrictive point in the exhaust for the biggest flow gain available at this position in the system. It's usually fitted alongside a Stage 2 remap, since the ECU needs to be told to expect the different readings the lambda sensors give once the cat's gone. It's offered in a choice of cat (De-cat, De-cat with GPF Delete), so you can pick the setup that suits how the car's used.
It's built for owners already committed to a serious power upgrade rather than a casual bolt-on, so pair it with the matching Milltek cat-back system for the full effect.
Because it removes the cat, it's intended for off-road and competition use. A de-catted car will fail an MOT emissions test and isn't legal to use on UK roads.
Specifications
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System Type: Large-bore Downpipe and De-cat
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Pipe Diameter: 76.2mm (3")
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EC Approved: No
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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
- 76.2mm (3") pipework
- Removes the factory catalyst for maximum flow (off-road and competition use only)
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- Audi RS3 Saloon/Sedan 400PS (8V MQB) - OPF/GPF Models (2019 onwards)
- Audi RS3 Saloon/Sedan 400PS (8Y MQB EVO) - OPF/GPF Models (2021 onwards)
- Audi RS3 Sportback 400PS (8V MQB - Facelift Only) - OPF/GPF Models (2019 onwards)
- Audi RS3 Sportback 400PS (8Y MQB EVO) - OPF/GPF Models (2021 onwards)
- Audi RSQ3 2.5T Sportback & SUV (OPF/GPF Equipped Models Only) (2020 onwards)
- Audi TT Mk3 TTRS 2.5TFSI Quattro (OPF/GPF Models) (2019 onwards)
Not every version fits every car in this list. Check the fitment shown for the option you select.
Not suitable for: the Audi RS3 Saloon/Sedan 400PS (8V MQB) - Non-OPF/GPF Models, which needs the Milltek Downpipe & De-cat Audi RS3 Saloon 400PS 8V MQB - Non-OPF/GPF 17+.
Installation
Some versions: Fits both OE and Milltek Sport Cat Back Systems - Requires Stage 2 ECU Software - NOTE to Customers - Due to Design of Turbo Waste Gate fitting a decat can cause metallic rattle to be heard more than the OE Cat Downpipe. Some versions: V2 Downpipe with Decat & OPF/GPF Bypass - Fits both OE and Milltek Sport Cat Back Systems - NOTE to Customers - Due to Design of Turbo Waste Gate fitting a decat can cause metallic rattle to be heard more than the OE Cat Downpipe - Requires stage 2 ECU software. 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 Filter-back Exhaust Audi RS3 Sportback 8Y OPF/GPF 21+.
Will it fit the Audi RS3 Saloon/Sedan 400PS (8Y MQB EVO) - OPF/GPF Models?
Yes. Milltek lists this part for the Audi RS3 Saloon/Sedan 400PS (8Y MQB EVO) - OPF/GPF Models as well as the other models in the fitment list above.
Does it fit the Audi RS3 Saloon/Sedan 400PS (8V MQB) - Non-OPF/GPF Models?
No. For that car, choose the Milltek Downpipe & De-cat Audi RS3 Saloon 400PS 8V MQB - Non-OPF/GPF 17+.
Is it road legal?
No. Removing the catalyst means the car will fail an MOT emissions test, so it is for off-road and competition use only.
Do I need a remap?
Yes. Milltek notes: "Fits both OE and Milltek Sport Cat Back Systems - Requires Stage 2 ECU Software - NOTE to Customers - Due to Design of Turbo Waste Gate fitting a decat can cause metallic rattle to be heard more than the OE Cat Downpipe". 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.
Will removing the cat cause a warning light?
Without suitable software it is likely to, as the ECU expects the readings a working catalyst gives. This is why Milltek pairs it with a remap.
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.