i bought a 2 1/2 year old dead 1991 745 volvo. i read about the air mass meter. the last owner said that they drove the 745 volvo in doing only 20 mph- so,i am thinking that the mass air meter is not working- i got the 745 volvo running fairly good- crank up with no gas and idles at 650 to 700 rpms. the check engine light stayed on. so, i went back to the bacis of wiring- clean all grounds even added another ground- installed a new positive cable. after doing this the check engine went out. i cannot drive the 745 volvo because i getting new tire on the car to see if the mass air meter is working- i have not run the code yet, too much going on. now, if the check engine light is off- is the system in working order? or what should i look for next? i have never worked on a 740 before. please i need to get this 745 volvo on the road- i deliver food to cancer people. the 745 make it easier to do this. thanks to everybody that has help with all there answers- kim--- sara rose foodbank