Hello, I'm Chris, a current Ford Lincoln Mercury employee.
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Common causes for your lean codes are low fuel pressure caused by a weak pump or a restricted fuel filter, intake gasket leaks and or vacuum and PCV hose leaks.
We find vacuum leaks by spraying the engine with ether and when a leak is hit the engine will rev.
The P0402 code can also cause your lean condition. The DPFE sensor is normally the cause of EGR valve concerns.
Here is the ford test for diagnosing 0402.
The DPF-EGR conrols the EGR valve. I sent a picture of it and its location. You will also see in the test per ford the DPFE is a possible cause in the last test.
Here it is again.