Thanks for the reply. Yes it is the O2S22 value that is staying constant at 0.03 v. Note that within same time frame of monitoring the O2S12 values are fluctuating as are both upstream sensor values. I do not have the CD but my vehicle is a 1998 Contour 2.5l (of course) automatic trans with approx 165K km. Manufactured in 1997. Already changed the Bank 1 Sensor 1 last year as it went 'bad' (CEL code confirmed that one. I guess the question is: is catalyst monitoring not done synchronously for both bank 1 and 2 and if not how is that governed and what values in the OBD-II software need to monitored to know if catalyst monitoring is active in conjunction for the sensors for Banks 1 and 2.
