2004 CEL question

My 2004 Rodeo with the 3.5L has a CEL, (code # I cannot recall) but a scan says "O2 sensor, bank 1, sensor 2" and something about the heater. We have replaced BOTH O2 sensors on what we believe to be bank 1--(drivers side), and had an Autozone scanner clear the code, but CEL has returned.

Any ideas?