I used to get 200 KM before I hit the reserve. After I put on the Hindle High-mount I'm lucky if I get 175 KM and only get 15-20 KM on the reserve as apposed to around 50KM before. So being the moron I am I just sat there scratching my head after every fill up and over looking the obvious. Maybe I'm just getting lazy in my old age and no longer want to take time out to think.
Anyway, all I had to do was dis-connect the battery, re-connect it, let the ECU reset and recalibrate the settings to accomendate the new pipe.
Back up to 200KM before hitting the reserve.