99 couger

99 couger is killing me, scanner says egr insuff flow, replaced egr valve and now get egr insuff flow and po171 bank 1 lean and po174 bank 2 lean, also replaced dpfe sensor. any ideas.

how does it run,fine or hard to start??
lean codes -vacuum leak, low fuel pressure
how many miles,has anything been done(service wise)tune up etc.

Hello, The car runs fine , if the light was not on you would not know there was a problem, just tuned up last summer.