Cat Back Exhaust

This part does not affect the base vehicle warranty.

The mountune Cat Back Exhaust for mk7 Fiesta ST reduces back-pressure and improves performance, whilst keeping cabin intrusion / boom to a minimum.

Designed and developed in-house by mountune's engineering team, the cat back exhaust utilises a Helmholtz chamber design in the rear silencer. This helps cancel out unwanted frequencies due to the way in which the exhaust gas waves are reflected. Despite being more complicated and therefore expensive to manufacture, this design ensures back-pressures remains low, providing the optimum in terms of performance, whilst removing as many of the unwanted frequencies and cabin boom as possible.

The staggered tail-pipe trim adds to the occasion and both trims feature laser-etched mountune logos.

As a mountune Performance product, this is also the only cat back exhaust available for your mk7 Fiesta ST that will not affect the base vehicle warranty, and comes with a limited lifetime warranty* against manufacturing defects.


  • High-flow cat-back exhaust design improves performance
  • Engineered Helmholtz resonator for a less intrusive, performance sound
  • High quality stainless construction with CNC welds
  • Staggered, twin-tailpipe trims with laser-etched mountune logo
  • Does not affect base vehicle warranty
  • Limited lifetime warranty

Please note: If this product is fitted with mountune Exhaust Isolator, we recommend using two isolators on the silencer only.

Compatible with all 3-door models globally and EU-only 5-door models. Customers in the USA please note there is a 5-door specific version, available at www.mountuneusa.com.

*Please contact us for warranty terms and conditions.

Customer Reviews

4.9 Based on 141 Reviews
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Filter Reviews:
    Colin M.
    United Kingdom United Kingdom

    High Quality

    A very well made exhaust with a deeper, louder exhaust note but not intrusive or 'boomy' at cruising speed on the motorway. It builds to a satisfying howl/roar at the top end of the rev range and also has a nice deep burble at fast idle on a cold start. Local garage fitted and cured a knock from underneath at the second attempt. The upward bend going over the rear beam was too close the underbody but after a slight adjustment, no more knocks. All in all very happy and would recommend this to anyone in the market for a new exhaust for their ST.

    Colin M. verified customer review of Cat Back Exhaust
    United Kingdom United Kingdom


    Very good really great quality exhaust came very quick and looks amazing

    United Kingdom United Kingdom

    Fantastic quality, not over the top

    As usual from mountune this product is extremely well made and presented. I was looking for a new exhaust for my fiesta for a long time as I believe ford really did the ST an injustice on the noise front. However as a daily drive and getting up EARLY for work I really did not want anything obnoxious or over the top. The mountune cat back exhaust is perfect for my needs, it adds just enough noise to draw attention and do some justice without intruding to much in the cabin with the windows up. Lift off at full throttle and you even get a few little pops and burbles which is great. So happy I took the plunge at Ford power live and bought this exhaust, definitely a must if your looking for an exhaust that isn’t over the top. I paired it with the mountune exhaust isolators and seems to be doing fine, no knocks and doesn’t swing around in the wind like my standard one did. 5 stars from me.