The Volkswagen Golf 2.3 VR5 150hp (Mk4 - 1997 - 2003) produces 150bhp and 205Nm in standard form. Our Stage 1 ECU tuning file raises output to 165bhp and 225Nm, a gain of 15bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.