Thanks for the information. I did ask that the current owner have the sensor replaced before I receive the car, but that may not happen before I have to pick it up. I definitely know about removing stubborn O2 sensors (having replaced several on other vehicles) and will soak the old one for at least 24hrs, if I end up making the replacement myself. Does anyone know if the wrench for the O2 sensor on my 1980 245 DL will fit the 1995 850 (btw, it is definitely a turbo!)?

This is what I am buying for $4200
http://www.craigslist.org/pen/car/101228325.html

I've been reading about common problems with these cars, so I intend to inspect the following:
1. Motor/transmission mounts
2. CV boots/joints
3. Water Hoses
4. Belts (timing belt has been changed)
5. Water pump (is it possible to inspect the water pump, other than for seepage?)
6. Brake calipers/pads

The car felt great when we drove it, but we had several others to look at and were short on time, so we made the best choice with what was available in terms of time and money. Besides, I have all of you wonderful people to bounce questions off!