Per the factory service manual:
P0443 - EVAP Control System Canister Purge Valve Circuit Malfunction. The PCM monitors the EVAP canister purge valve circuit for an electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified purge duty cycle by PCM command.
- VPWR circuit open
- EVAP canister purge valve circuit shorted to GND
- Damaged EVAP canister purge valve
- EVAP canister purge valve circuit open
- EVAP canister purge valve circuit shorted to VPWR
- Damaged PCM
Monitor EVAPPDC PID and voltage between EVAP canister valve signal and PWR GND in output test mode with key ON engine OFF (or in key ON engine RUNNING mode). EVAPPDC PID at 0% and voltage less than 1.0 volts (or EVAPPDC PID at 100% and voltage less than 0.5 volts) indicates a hard fault.
This code could be due to something getting damaged by the road debris. The EVAP canister purge valve is located in the right rear of the engine compartment, but the EVAP canister is located near the fuel tank.
The P0174 - System too Lean (Bank 2) has been addressed on this forum before, so I'll let you try out the handy "Search this forum" tool from the Taurus forum main page to get details on possible causes of that code.
-Rod