Thanks heaps for your quick response "White850Turbo".

Yes my V70 is the non-turbo model and our mechanic replaced both the front and rear sensors.

I was wondering if you think that having a bosch non genuine sensor would definantly cause this fault and not another problem causing the car to run ...

Hi I own a 1999 V70 and recently had a dash light appear indicating a front O2 sensor was U/S. I had the front and rear O2 sensors replaced with new Bosch Non Genuine sensors and the code reset, later that day the dash light re-appeared. I then took the car to a volvo specilist and had the sensors ...