Requires mandatory ECU reflash Cobra Sport performance exhausts enhance the sound, looks and quality of your vehicle giving you the ultimate driving experience. Our sports exhausts range is fully guaranteed to give you assurance of our quality. This Ford Focus Mk4 ST cat back performance exhaust is made in 3"/76.2mm pipework and fits from the Catalyst section backwards (Cat-back) replacing the GPF, centre and rear sections. This non-resonated exhaust makes the system louder as it excludes the centre silencer and therefore, has a sportier exhaust note. This exhaust however, is also available as a resonated version (including centre silencer) which is a quieter option. IMPORTANT: this exhaust removes the GPF filter and will require engine tuning at time of fitment to cancel the EML light. Fitment to GPF equipped models is for motorsport and off road use only. Cobra Sport Exhausts provide the performance exhaust solutions for the Mk4 Focus STs raced by the MB Motorsport accelerated by Blue Square and Motorbase Performance teams in the 2021 Kwik Fit British Touring Car Championship. This technical partnership allows us to test our products on track at the highest level of British Motorsport. The experience gained from the competitive track environment is fed back into all of our road going performance exhaust systems. Press Release The Ford Focus ST has long been a favourite amongst hot hatch fans, especially in the UK, ever since the launch of the Mk1 ST170 back in 2002. The Mk2 ST moved Ford’s hot hatch game on even further in 2005 when they fitted it with a thundering 2.5 5-Cylinder engine. And in 2012, despite losing a cylinder and half a litre of capacity to its predecessor, the Mk3 still sold in the thousands. Every generation of Focus ST has had seemingly limitless tuning potential thanks to their horsepower-hungry engines and playful handling characteristics. Cobra Sport have enjoyed enormous success in this field, with their performance exhausts for both the Mk2 and Mk3 Focus STs being amongst the best-selling systems in the market. Aiming to replicate this success, Cobra Sport are proud to announce their latest product range for the Ford Focus ST Mk4. Over the past few months, their Research and Development team have been hard at work developing an extensive range of performance exhaust systems that will cater to the needs of any fast Ford enthusiast. Also available in the range is Cobra Sport's Cobra’s unique ‘Venom’ range. For those who want a further improve sound levels, the Venom exhaust removes the rear silencer to offer the biggest sound increase whilst keeping a sporty exhaust tone(+8.5db in GPF-Back Venom configuration). Like all Cobra Sport exhausts, the Mk4 Focus ST systems are TIG-welded from high-quality T304 stainless steel and the mandrel-bent pipework is a full 3in (76.2mm) in diameter for maximum sound and tuning potential. With over 25 years in the performance exhaust industry, each Cobra Sport exhaust system is designed, manufactured and tested in Sheffield, the heart of the UK steel industry. Cobra Sport utilise TIG-welding techniques to ensure a flawless finish and quality that you can rely on.