sounds like the motor is running lean, not enough fuel.
system to lean bank one 02 sensor ?
Perhaps a clogged fuel filter.
check the maf sensor
Check your Plugs and coils
Trouble code P2195 means: Lack of HO2S-11 Switching, Sensor Indicates Lean
Trouble code P0171 means: Fuel System Too Lean (Cylinder Bank 1)
all controlled by computer,see dealer for diagnostics
Could be sucking air into intake.
If you are getting a Lean code then it is probably being caused by the intake plennum gaskets. This is a common problem on the Windstar. The fix is relatively easy.
The fuel mixture is wrong in both banks. Improper fuel to air mixture is called lean. Running a code test on the vehicle may show what could be causing the problem.
running lean. too many possibilities to narrow down