The Seat Leon 1.8i 20v 125hp (1M - 2000 - 2006) produces 125bhp and 170Nm in standard form. Our Stage 1 ECU tuning file raises output to 135bhp and 185Nm, a gain of 10bhp and 15Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.