850 turbo intermitent stalls every time when warm. 150,000 miles, all maintenance to date, running perfect until one month ago. Now at local non factory Volvo repair for three weeks. They can not figure it out. Throttle relay replaced, cam sensor, ignition, fuel pressure, plugs, wires all checked OK. Starts perfect, warms up, engine stalls for seconds every minute, whether giving gas, coasting etc. Finally stalls and will not start until cold. Factory Volvo repairman also ran all codes and can not figure it out. Said it will not allow him to even run diagnostic. Local Volvo repairman ready to give up. He mentioned he could try and replace two O2 sensors or computer, but I would have to buy those items to try, and they may not fix the problem. Car is totally unusuable. Any suggestions would be appreciated.