Likely three separate faults:
1: P0401 - EGR ports clogged or DPFE faulty. Plenty of history on this in prior posts.
2: P0420 - Cat converter below established efficiency. Also plenty of history in prior posts.
3: P0171 & P0174 - Probable air leak in intake system. Might be intake gaskets, PVC hose, or any other part of the intake tract after the MAF sensor. Once again, plenty of history in prior posts.
Use the code(s) as your keyword for a search.
Steve
