The GMC Envoy 5.3 V8 290hp (2002 - 2010) produces 290bhp and 441Nm in standard form. Our Stage 1 ECU tuning file raises output to 310bhp and 460Nm, a gain of 20bhp and 19Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.