As with all new models, the Mk4 ST Estate is fitted with a GPF (petrol particulate filter), which limits the potential of the engine, leading to a muted and slightly disappointing sound.Cobra Sport's engineers have developed a solution in the form of their new PPF Delete. This high-quality, 3in (76.2mm) TIG welded stainless steel performance exhaust removes a significant restriction in the exhaust system.A direct replacement for the OEM part, the Cobra Sport GPF Delete is the most cost-effective way to improve the sound of the stock Mk4 ST Estate. A simple ECU reflash will be required at the time of fitting to prevent engine warning lights illuminating.Like all Cobra Sport exhausts, this product utilises precision TIG-welding techniques for exemplary fit and finish a feature that sets Cobra Sport apart from other manufacturers.