2004 Micra 1.4 Automatic K12 - P0132 Code

[Pangit]

In the last week or so, my wifes car has started to get a check engine light come on on the dashboard. Idling is also a bit erratic on occasions, and it is sometimes sluggish when pulling away/accelerating. When I check the engine code it says P0132. I read somewhere that it could be spark plugs, so since I had already bought a set as they were due for a change, I changed them. The light has not come back on yet, but there is no improvement in the idling. There is so much info here and elsewhere on O2 sensors, I thought I would ask the question......what should my next steps be before I go out and buy a new sensor. Any input would be appreciated.

 

[Pangit]

After I wrote the above post, the check engine light came on, with the same fault code. After a couple of days it went off again, and has stayed off. The slightly rough idling has disappeared, as has the sluggish acceleration/pull away..............someone mentioned to me that maybe there was a bit of water in the fuel which has now flushed out....could this have been the cause of my problems ?