P0135 and P0155 engine codes on my 2001 Ford Mustang 3.8L

Question

I am working on a 01 mustang with a 3.8 V6. It has continuous hard codes of PO135 and PO155 which are heated 02 sensor issues, Bank 1 sensor 1 heated 02 and bank 2 sensor 1 heated 02 circuit. Tested fuses, Relay's, installed new sensors, checked connection, Car has a modified exhaust system. Flow master w/o headers. Has many leaks in welded areas, but not rotted. smoke tested to check. Replaced coolant sensor. I use a fairly new Genisis scan tool. I do not have a wiring diagram of the 02 system, so if the is any suggestion or other test procedures would be greatly appreciated.

Answer 1

i will be following your post as I am having the same issue with my 2000 Ford Mustang v6 3.8 2 dr convertable base model