I have a '94 854 Turbo, recently it has had a poor cold idle. The idle problem would eventually fix itself after you drove it around for about 30 minutes. So I finally took it to a mechanic who specializes only in Volvos. All he replaced was a a few Turbo hoses that supossedly had holes in them, and the plugs and wires. He said that the o2 sensor is bad, but it wouldnt cause the car to act like this. I am extremely skeptikal it will run right, but I go to pick it up today. Could these few things have been my problems?

Thanks!
~Cody Julian