what could this be? oxygen sensor or in relation to the heater circuit itself(fuse maybe?)
obd codes os2 heater ckt low and 0s2 heater ckt malfunction on 2003 Saturn Ion
There is a heater element in the O2 sensor that heats up the sensor, this heater element can fail, and cause this fault. Check the fuse, but you will likely need to replace the sensor to remedy the problem.