Hello.
 

New to the forum and I have a few questions. First I love this car although it's not mine ( it's the wife's ) I thought I would voice my questions here. She has the engine light on and we took it to a Mechanic and he stated it was the 02 sensor. How hard would it be to replace this? My second question has all the xc70s wagons come stock with turbos? Also while looking at her cd player I've noticed that her h/u has a changer button on it but I do not know where to located it's magazine if there is one. Thanks for stopping past my thread.

O2 sensor replacement - be patient with the right tools. Connector will take some effort to get to as its below the intake hose on the right hand side toward the firewall.

Yes, all XC70s came stock w/ turbos.

CD changer should be in the back - check the side panels.