Codes P0135 and P0154, upstream O2 sensors?

Hi,

I attached the entire wiring schematic for the powertrain management circuits. I highlighted all wiring related to the oxygen sensors.

Take a look through the schematic and let me know if this helps or if you have other questions.

Take care,

Joe

See pics below. Note: The schematics were 5 pages long. I cut each page in half to make them readable for you. I also overlapped them so you can follow from one to the next.