Milltek Cat-back Exhaust for BMW 1 Series M140i 3 & 5 Door (F20 & F21 LCI, Non-OPF) (2015-2018) – Sharper Sound, Reduced Back Pressure
This is Milltek's cat-back system for the BMW 1 Series M140i 3 & 5 Door (F20 & F21 LCI, Non-OPF). It replaces everything from the factory catalytic converter rearward with wider-bore pipework, a re-profiled mid-pipe and silencers tuned specifically for this platform, cutting back pressure and sharpening the exhaust note. The factory catalytic converter stays in place, so the car's emissions hardware is left as standard. It's offered in non-resonated or resonated versions and 5 tailpipe finishes, so you can pick the setup that suits how the car's used.
It's aimed at owners who want a noticeably different sound and a genuine, if modest, flow improvement without touching anything upstream of the cat: a straightforward bolt-on that doesn't need a remap or any other supporting mods to enjoy.
Specifications
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System Type: Cat-back
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Pipe Diameter: 66.5mm (2.62")
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EC Approved: No
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Race System: No
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Fitting Time: approx. 1 to 1.5 hours (Milltek figure)
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
- 66.5mm (2.62") pipework
- Replaces the standard exhaust from the catalytic converter back, so the factory cat is retained
- Choice of 5 tailpipe finishes: GT-90 Burnt Titanium, JET-90 Carbon Fibre, GT-90 Cerakote Black, GT-90 Polished, GT-90 Titanium
- Resonated (quieter) or non-resonated (louder) versions
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- BMW 1 Series M140i 3 & 5 Door (F20 & F21 LCI, Non-OPF) (2015-2018)
Not suitable for: the BMW 1 Series M140i 3 & 5 Door (F20 & F21 LCI, OPF/GPF Only), which needs the Milltek Cat-back Exhaust BMW 1 Series M140i 3dr & 5dr (F20 & F21 LCI, OPF/GPF Only) 19-20; the BMW 1 Series M135i 3 & 5 Door (F21 & F20, Non-xDrive), which needs the Milltek Cat-back Exhaust BMW 1 Series M135i 3dr 5dr F21 F20, Non-xDrive 12-16; the BMW 1 Series 118d & 120d M Sport 3-door (E81), which needs the Milltek Cat-back Exhaust BMW 1 Series 118d 120d M Sport 3dr E81 07-12.
Installation
Milltek quotes a fitting time of approx. 1 to 1.5 hours. We recommend professional fitting on a ramp. Once fitted, check the tailpipe alignment and re-check all clamps after the first few hundred miles.
Upgrade Further
Also available from Milltek for this car: Milltek Large-bore Downpipe BMW 1 Series M140i 3dr & 5dr F20 & F21 LCI, Non-OPF 15-18.
What's the difference between the resonated and non-resonated versions?
The resonated version adds extra silencing for a quieter, more refined tone. The non-resonated version leaves it out, so it is louder and more aggressive.
Which tailpipe finishes are available?
You can choose from: GT-90 Burnt Titanium, JET-90 Carbon Fibre, GT-90 Cerakote Black, GT-90 Polished, GT-90 Titanium. The finish is cosmetic and does not change the sound.
Does it fit the BMW 1 Series M140i 3 & 5 Door (F20 & F21 LCI, OPF/GPF Only)?
No. For that car, choose the Milltek Cat-back Exhaust BMW 1 Series M140i 3dr & 5dr (F20 & F21 LCI, OPF/GPF Only) 19-20.
Is it road legal?
Milltek does not list EC approval for this part. Any exhaust used on the road must still meet noise and emissions rules, so check the requirements where you live.
Do I need a remap?
No. It fits behind the factory catalytic converter, so no software changes are needed.
Does it keep the factory catalytic converter?
Yes. It fits behind the factory catalytic converter, which stays in place.
How long does it take to fit?
Milltek quotes approx. 1 to 1.5 hours.
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.
