Cel From The O2 Sensor Heater?

[cmfhsu]

I've got a '98 lx470 that's been really faithful and reliable but a few days ago the CEL came on, so i brought it to autozone and pulled the codes. I pulled a P0155 o2 sensor heater circuit malfunction (Bank 2 Sensor 1). I cleared it and drove for about 40 or 50 miles without it turning on again. When i got home however, i took it out and the CEL came back on. I haven't checked the code for this CEL, but i'm pretty sure it's for the same reason. What causes an o2 sensor heater circuit malfunction? I did recently hit a deer and had parts replaced, so do you think that could've caused it?

[SKperformance]

The heater is used at start up to heat the o2 sensor to the right level for correct readings.

It either works or doesn't , once it is off at start up it stays off. The wire or senor is damaged.