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Downpipe / Sports Cat [Mk4 Focus ST]

The mountune Downpipe / Sports Cat has been engineered for the Mk4 Focus ST to reduce exhaust back-pressure at the turbocharger, allowing faster response and additional power.

Featuring a large diameter motorsport-style, 200-cell count metal substrate honeycomb catalyst, to ensure effective, ultra high-flow performance, the mountune  downpipe sports cat is also constructed of 3” AISI 304 stainless steel mandrel-bent tubing with TIG-welded joins throughout for performance, reliability and aesthetics.

Additionally, robust OE-style mounting brackets and hangers are utilised to maintain perfect alignment and OE-like fitment and also incorporates an 8” stainless steel flexi section to help absorb shock and prevent OE hanger failure.

Revised engine calibration will be required for optimal performance and will emit the EML without it, but by simply replacing your downpipe and removing the inherent restriction, you can expect a peak performance gain of 10PS and 10Nm, with an even more substantial torque increase spread across the entire rev-range. 


  • 10PS / 15Nm peak power / torque increase
  • Large diameter motorsport-style, high-flow 200 cell catalyst
  • 3” AISI 304 mandrel bent stainless steel tube
  • Robust OE-type mounting bracket and hangers
  • 8” stainless steel flex joint
  • Compatible with all exhaust systems that retain the factory break point
  • Supplied with required gasket and hardware
  • TIG welded construction

Whilst this product will pass current UK MOT tailpipe emissions regulations, it utilises a high-quality motorsport catalyst, which is therefore designated for off-road use only in the UK. 
If outside the UK, please check your local territories laws and regulations relating to emission requirements and motor vehicle safety standards prior to purchasing.

    Customer Reviews
    5.0 Based on 16 Reviews
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    Filter Reviews:
      Jason A.
      United Kingdom United Kingdom

      Sport cat

      I had the sports cat fitted along with the sport gpf ready for the m365 upgrade!

      mountune Downpipe / Sports Cat [Mk4 Focus ST] Review
      gary h.
      United Kingdom United Kingdom

      Sports cat

      Great service as usual highly recommend Mountune's. I travel 140 miles and it's worth the drive to have there fitting service .

      United Kingdom United Kingdom

      Down pipe

      Great bit of kit! Pretty easy to swap out on a car lift, few stubborn fixings, but came apart with a bit of persuasion!!

      mountune Downpipe / Sports Cat [Mk4 Focus ST] Review