1998 Chevy Blazer p0135 code

Please help me i have a 1998 Chevy Blazer 4door 4x4. I just put a new crate engine in and am having trouble with it trowing a p0135 code (heater circuit malfunction) bank one sensor one, anyways i have replaced it three times along with my catalytic converter and still the code comes back any ideas will be helpful thanks..
It must be a wit=ring problem then. That is all that is left. Look for broken or pinched wires.
 

Being way2old is why I need help from younger minds After replacing the same sensor three times, you must realize that it’s not the sensor.
Because you have just replaced the engine; I would be looking for something you missed reconnecting or damaged.
The first thing that comes to mind are the O2 ground circuits; at the back of both cylinder heads there should be wired eyelets that should be bolted to the heads.
Next would be to make sure that there is battery voltage at the wiring harnesses O2 connector’s pink wire. This voltage will only be there until the computer sees that the engine is up to operating temp & that the O2’s are on line, sending a return signal.