One problem related to mass air flow sensor has been reported for the 1999 Volvo V70. The most recently reported issues are listed below.
11/12/04 mass air flow sensor replaced 12/16/04 map sensor & shut off valve replaced 3/15/05 shut off valve replaced again! 1/18 05 master window switch pack replaced - 5/31/05 master window switch pack replaced again!! 3/17/05 electronic throttle control module replaced!!! 5/9/05 oxygen sensor and abs control unit replaced. When the throttle control module failed in March 2005, my 1999 Volvo V70 had only 55,000 miles on it! I was on the expressway when my car lost power and had no way to get back onto the road safely. . . . . I have spent over $4000 in the past year replacing electrical control units in order to make this car safe. The check engine light came multiple times over the past year. I am afraid to drive this car for fear of something else going wrong with the electrical system. I have four small grandchildren who are with me at least three days a week.