Hi, I am John Mc, a Ford dealer tech. I hope I can help you quickly and accurately. One moment while I work on your problem.
P0174 is a lean condition code. I would carefully inspect for vacuum leaks with the engine running. If you cannot find the leak by ear or by eye you can use some carb cleaner and spray it around on the intake and vacuum lines. When the rpms of the engine change you have found where it is sucking air. If no leaks are found you can try removing the mass airflow sensor and thoroughly cleaning it.
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