Emission System Service Required is the message appearing on my S80 any ideas whats wrong and how much this one will cost?

 

As tech would say, Under that message it could be anything, Most common thing is its the o2 sensors:

When my emissions system service came on(came on 2 different occasions)-

1.)mass air flow sensor
2.)throttle body

you need to pull the codes.

 

could be an assortment of things. Usually it's the 02 sensor, but could also be a bad ect sensor, bad secondary 02, bad tps (etm), bad map reading, etc.

 

Best thing to do is pull the codes first and see what they say.