O2 Sensor Code P0134

[Gabriel5501]

Hey Everyone, so I just installed a new catalytic converter and new oxygen sensors. As I was splicing in the front sensor I noticed that the wires had pulled out of the harness on the ECU side. After getting the wires all spliced in, I tried (without much success) to reinsert the wires back into the harness. This did not work out, and I kept having all kinds of problems with the car stalling, throwing all kinds of codes, etc.
Tonight I pulled out the old wires and spliced in new wires (14g using weatherproof butt connectors) from the O2 sensor up to just before the ECU. After a little bit of a rough start it seems to start and run fine, but it keeps throwing "P0134 O2 sensor circuit no activity" I am going to double check all my connections however, when I spliced the wires in there were 2 white wires. Do they have to be in a specific order (can I wire them backwards), or are they interchangeable?