The Volkswagen Golf 1.9 TDI 115hp (Mk4 - 1997 - 2003) produces 115bhp and 285Nm in standard form. Our Stage 1 ECU tuning file raises output to 145bhp and 360Nm, a gain of 30bhp and 75Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.