Does the car continue to show codes? If you are reading them using VIDA (the Volvo software,) or other reader, post the codes. One suspect would be the ETM (electronic throttle module,) but that would throw a code at some point if the parameters get too far off. Is you coolant temperature gauge work...

Indeed, later ETM also had problems. Also look around for vacuum leaks. Look at the large rubber hose after the air filter, pinch it everywhere look for a crack, all smaller hoses around too. Also need to use a good brand of MAF, I think it's Bosch on the turbo eng. Also look at the wires near conne...