The BMW E91 3.0d owner wanted to find out what changes had been made before purchasing the car. Analysis of the previous ECU file showed that diagnostic fault reporting had been disabled. AutoChip installed its own calibration and restored fault-code processing so that faults could be detected.

With the factory software, the dyno recorded 227 hp and around 550 Nm. After the new calibration, the result was 296 hp and 702 Nm. A repeat run again produced 296 hp and approximately 698 Nm, confirming a similar result.

Engine speed fluctuations were observed at around 1,500 rpm during testing. The video raises a possible gearbox issue, but its cause was not diagnosed and no repair is confirmed. The symptom should therefore be treated as a reason for a separate inspection.