DTC P0171 System Too Lean (Bank 1); DTC P0172 System Too Rich (Bank 1); DTC P0174 System Too Lean (Bank 2); DTC P0175 System Too Rich (Bank 2): Wiring Diagram
WARNING: This page is about a different car, the 2007 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
Refer to DTC P2195 .