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P0174 is a lean code. I usually see this code commonly on these engines when the PCV line fitting splits open from age. It gets soft and starts to collapse everytinme the engine is started then opens back up when the engine is shut off. This slowly splits the rubber fitting over time. It comes off the bottom of the intake plenum just behind the throttle body if memory serves. Check this connection. Observe fuel trims while the engine is running. If they are beyond 25 then its probably this fitting. Have to buyit through Ford.
The P0181 is a fuel temp code. Check the connection to the fuel temp sensor and observe fuel temp in the scan tool. Check wiring to the fuel temp sensor. If the wiring and connector are ok then suspect the temp sensor.
Shawn
That makes even more sense. 171 is lean bank 1, 174 is lean bank 2. Deffinately a vacuum leak or low fuel pressure. I would bank on the PCV fitting leaking.
ASE Certified Technician
PA Certified Inspection emissions, ASE Brakes Suspension, Lead diagnostic Tech.20 years exp