Isn't a code 41 the o2 sensor heater circuit? Code 01 is usually the o2 sensor circuit. You can probe the wires for the heater circuit on the o2 sensor with a multimeter to see if you have continuity. If you do, then the problem causing the code 41 is on your engine harness, not with the o2 sensor. 4-wire o2 sensors aren't cheap.

I can get you the wire info if you need it, as well as an ECU pin # and the locations of the wires on the bulkhead connectors if you want. I just have to dig it up. I only know this because I had to wire in a heater circuit to the ECU because my car did not have one on the engine harness. Checking it first is free.

Is this the original engine that came in your car?