KYOSTAR Catless Downpipe for 2017+ Audi RS3 8V TT RS 8S EA855 2.5T Upgrade your 2017+ Audi RS3 8V or Audi TT RS 8S equipped with the EA855 2.5T turbocharged five-cylinder engine with the KYOSTAR Catless Downpipe. Designed as a performance-oriented replacement for the factory downpipe configuration, this system provides an upgraded exhaust flow path for high-performance Audi applications. The catless downpipe design removes the catalytic converter section from the exhaust