Stage 1 calibration broadens the usable torque band of the 1.6 HDI while keeping factory refinement. EGR flow and its diagnostics are fully disabled, lowering soot build-up and keeping the intake charge clean. Torque, boost and smoke limiters are rescaled with balanced air-fuel targets so the five-speed gearbox stays within OEM load margins during daily driving. Cold-start, idle and part-throttle zones are retuned to preserve stock fuel economy on cruise yet give a sharper pedal response in traffic.