After manually checking my fuel consumption, it gave me 17l/100km. This is about 50% more then what the OBC tells me.
I drive a mixture of city and highway driving, however work is only 20 minutes from home so maybe the engine has not warmed up and hence is still running rich???
The problem is that the idling is fine, acceleration is fine but the fuel consumption is too high. Could this still be a faulty O2 sensor? (I thought the signs of a faulty O2 sensor is poor acceleration, rough idling and high fuel consumption?)