Opel Corsa high fuel consumption in town.

The Opel Corsa B and C 1400 has very high fuel consumption in town. In the video I discuss a problem found with ground loops where the ECU ground is 0.1V higher than the lambda sensor cousing an offset and incorrect readings. Which makes the fuel mixture richer. This problem is solved on other models where the factory added another ground wire between the engine and ECU. The solution is to not earth the vehicle body directly to battery negative, but earth the body to engine which puts ECU and Lambda ground voltages much closer. The problem is especially on one wire lambda sensors. In newer Corsa vehicles they added another ground wire from the factory. Average consumption before mod was about 8.15km/l, filled up again one week after video got 9.25km/l with more accurate fill.