Milltek GPF/OPF Bypass for BMW 1 Series M135i xDrive 5 Door (F70 OPF/GPF Equipped) (2024 onwards) – Filter Delete, Motorsport Use
This is Milltek's GPF/OPF bypass pipe for the BMW 1 Series M135i xDrive 5 Door (F70 OPF/GPF Equipped). It replaces the section of pipe housing the factory petrol particulate filter with a straight-through pipe, clearing the last major restriction left in a modern turbocharged petrol exhaust once a de-cat and remap are already in place. It's offered in OE downpipe and milltek OPF back system only or OE downpipe and OE OPF back system only versions, so you can pick the setup that suits how the car's used.
It's aimed at owners already running a de-cat and a supporting remap who want to clear the final restriction in the system, not a bolt-on for a car that needs to stay road legal.
Because it removes the particulate filter, it's intended for off-road and competition use. A car with the GPF/OPF removed will fail an MOT emissions test and isn't legal to use on UK roads.
Specifications
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System Type: GPF/OPF Bypass
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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
- Straight-through pipe in place of the factory petrol particulate filter (off-road and competition use only)
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- BMW 1 Series M135i xDrive 5 Door (F70 OPF/GPF Equipped) (2024 onwards)
Not suitable for: the BMW 1 Series 128ti 5 Door (F40 OPF/GPF Equipped), which needs the Milltek GPF/OPF Bypass BMW 1 Series 128ti 5dr F40 OPF/GPF 21+.
Installation
Some versions: To fit to OE downpipe and Milltek OPF Back System Only. Some versions: To fit to OE downpipe and OE OPF Back System Only. 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 BMW 1 Series M135i xDrive 5dr F70 OPF/GPF 24+.
Does it fit the BMW 1 Series 128ti 5 Door (F40 OPF/GPF Equipped)?
No. For that car, choose the Milltek GPF/OPF Bypass BMW 1 Series 128ti 5dr F40 OPF/GPF 21+.
Is it road legal?
No. Removing the particulate filter means the car will fail an MOT emissions test, so it is for off-road and competition use only.
Do I need a remap?
A suitable remap is strongly recommended, as the engine management needs to account for the change in flow and sensor readings. Speak to your tuner before fitting.
Can I use it with my standard exhaust?
Yes. Milltek lists it for use with the factory (OE) exhaust system.
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.
