I have a 1999 S70 T5 w/ approx. 98,000 miles on the odometer and the check engine light has been on for a while now. My service tech told me that the error code was for a bad MAF sensor, however he indicated that the car seems to be running fine. He cleaned the connection and the light went off for about a day, then came back on. He suggested that I just keep driving the car as is. Problem is this, my fuel economy has dropped by about 10 to 15 percent since the light came on. Ok, so here's my question, will it hurt the car to keep driving it w/o replacing the MAS sensor? Is it easy to replace, in other words, can a somewhat mechanically inclined person do the job in an hour or so? If so, what is the part number and where is the best place to order the part? Sorry for the long message!