If it is a P0038 OBD-II code, I would do a visual inspection of the Bank 1, 2 HO2S (heated oxygen sensor) and its wiring harness. If there is any damage to the sensor or any damage to the wiring, fix it. Also, check for bare wires where the wiring enters the sensor for possible fatigue and shorts. Make sure the wiring is routed away from the exhaust. Repair the wiring or replace the sensor if necessary.
If everything appears okay, unplug the Bank 1,2 HO2S and verify that there is 12 volts B+ present with the key on engine off, (or ground is present, depending on the system). Verify the heater control (ground) circuit is intact. If so, remove the o2 sensor and inspect for damage. If you have access to resistance specifications you can use an Ohmmeter to perform a resistance test of the heater element. If there is infinite resistance replace the o2 sensor..