JimBee, heating up that stuck oxygen sensor is definitely the way to go to break through the rust. Just be careful not to overdo it or you could damage the surrounding components as you mentioned. I dealt with a similar stuck sensor on my old 850 during a heatwave last summer. The extreme hot weathe...

It seems you are definitely not alone in experiencing this issue with faulty steering wheel controls, as another member chimed in saying they are having the exact same problem in their Volvo XC60. Unfortunately from reviewing this thread and other similar discussions online, it does not appear there...