There has been some discussion on o2 sensors in various threads and didn't want to highjack them.
On the weekend, car had check engine light come on with just code 12 which points to o2 sensor heater. After couple of days, code 2 came on as well which indicates bad o2 sensor. So, I was pretty convinced that I need to get a new sensor to fix both issues.
Yesterday I cleared all the codes and now only code 12 is back. I am planning to order a new sensor and try it but wanted to see if anyone else had seen just the code 12 and found something else to be an issue e.g. a short or a grounding issue? On M104, it is easy to test the heater circuit since the connection is under the passenger side carpeting. On M119, the connector is underneath the car and that means waiting till the weekend to clear out the garage and lift the car up.
thanks for any pointers.