Im suddenly losing power in my '98 s70. I start off okay but when I press on the gas pedal nothing happens, the tach needle does'nt even rise up to 2000, not even when the pedal touches the floor, then it goes into kickdown and suddenly lunges foward and its okay for a while, goes thru the gears then it happens again......quite dangerous..What could be causing this?? The codes say some of the cylinders are misfiring and my independent volvo guy says that could be caused by a faulty 02 sensor. What do you think?

 

It could be many things.

Did he tell you what the codes are?
It could be a mass flow sensor,Throttle position senssor,Dist cap and rotor, Plugs,wires,O2 sensor, ETC