O2 Sensor / Dies while stopped
 

I recently purchased a v70. The car itself says 2003 but the title says 2004...
Anyways, the guy who sold it to me told me it had a bad O2 sensor. I took it to an autozone during test drive and had it confirmed. I've already put about 300 miles on the car, and it has died twice on me. Once was at a red light, and once was at a stop sign. It happened several days apart and after driving a decent amount.
I drove 120 miles in one day with no problem, however.
error code: P0037 Heated Oxygen Sensor Heater Control Circuit Low Bank 1 Sensor 2
My question is: is it likely that the O2 sensor is the problem? If so, what can I do about it?
I do have a similar v70 with a busted engine I could take parts from, and I am interested in DIY but will take it somewhere if necessary.

Well, you know the sensor is bad, so replace it first and go from there.

the O2 sensor has four wires - two for the heating element, two for the sensor. About the only difference from model to model is the design of the connector and harness length - in fact you can buy a universal Bosch O2 sensor for about $35 that you'd splice into the existing wiring harness. Your car has two sensors - one before the catalytic converter, one after. The front controls fuel trim, the rear measures cat efficiency. It looks like your code is saying the heating element on the rear sensor is bad - thus it needs to replaced to clear the CEL. Since this doesn't alter fuel trim, the car should drive normally. As far as DIY goes, since the sensor plugs into the exhaust, its a lot easier for a shop with a lift to access. Also on 15 year old cars, the sensors can rust in and may take some leverage and clear access to remove by dropping the exhaust down. You'd need to go under the car and see if you can easily reach the part or leave the job for a shop.