P2626 sounds more like a hard wiring issue. O2 sensors are not very fragile so I doubt you could have damaged it during assembly/disassembly. You can compare internal electrical resistance and compare with the other O2 sensor.
It could also be a resistance out of sync issue with the decel shut off.. Ie tge computer is looking for no fuel, but there is fuel. Swapping in catted tune, mike w hasn't got back with me since I sent him the issue and datalog on Monday morning.