Your self adaptation reached limits.
P0170 - Self adaptation of the partial load or idle mixture formation for right cylinder bank to limit value of ME-SFI control module (N3/10)
P0173 - Same thing just for Left cylinder bank
Could be air leak, fuel injectors of diaphragm-type pressure regulating valve, wear to engine
I would suggest to check all four CO2 (oxygen) sensors or your air supply tube to throttle valve body came loose.
1999 ML320 203K miles
2003 Lexus GX470 268K miles
1980 280SE EURO W126 156K miles 142mph SOLD
1984 300D TURBO DIESEL W123 SOLD