Odd DME behavior-emission issues

[jontalk]

After speaking with the chief technician, very in depth voltage scans of all sensors etc were done and checked out.

Furthermore I incorrectly stated the codes that have been showing up most of the time which are: P0133 (oxygen sensor ageing bank 1); P1275 (oxygen sensor ageing delay, bank 1) It threw these two codes in the late Spring. Shortly afterward the car was serviced and the bank 1 sensor was swapped to the other side. A few months later it threw the code again and it had moved along with the sensor. Then they replaced the sensor with a used one and it seemed OK until a week or so ago, when it threw the ageing code again. At that point they updated the DME and this brings us to the current situation.

The technician that works on the car is VERY seasoned, honest and wants it to work as it should. He has said he hasn't seen this sort of odd behavior before though the gas mixtures in CA change from season to season and the car does not get driven very often either. Hope that fills in the missing blanks.