1995 85o Turbo; Acceleration problems

My '95 850 Turbo is well maintained and run like a champ (quick as hell)
until recently. I have been experiencing issues with my 850 Turbo for
about 4 weeks, which manifest by rough idle when starting and horrible
acceleration and gas consumption. I had the air sensor replaced and that
helped for about 100 miles. Then my engine light came back on. I have had
diagnostics run by two different mechanics and they tell me my plugs and
injectors are fine. I haven't wanted to go to a Volvo dealer to have it
looked at because in Chicago they want to replace everything possible.
Does anyone have any ideas of what may be causing these problems for me?

 

I don't know if this will help, but on my 1996 850 wagon I noticed big
improvement when I changed an air filter. Sometimes its the little things
that will make all the difference. Air filter, gas filter, plugs, rotor,
wires, flame trap, throttle body cleaned. From all the newsgroup posts I see
that does are most common problem areas.