The Audi S4 3.0 TFSI 354hp (B9 - MK1 - 2016 - 2019) produces 354bhp and 500Nm in standard form. Our Stage 1 ECU tuning file raises output to 400bhp and 550Nm, a gain of 46bhp and 50Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.