Thanks Klaus. I have been to the auto parts store twice and used their reader with no luck, meaning no codes. I do not get any codes on my reader either. It is not the oil change service message. It reads "ENIGINE SYSTEM SERVICE REQUIRED". It comes and goes, but comes more often now. I just cleaned the throttle body, and used a Volvo gasket on reinstall, and the message still came back.
I can sometimes get the message to clear by turning the ignition on and off a few times. I have even done this while driving, because I believe this message causes the cruise to be disabled at times(cruise indicator light wont come on and cruise doesn't work), so being a manual shift car I can turn it off and on without hitting the starter while driving. Then message clears and cruise works.