Hey guys I have a 98 2.5 engine in my manual 99 ranger. Its been idling really rough, feels like it's going to stall, but hasn't yet. It drives fine, although my CEL came on while driving and I got it tested and was told it was probably my O2 sensor. (I forget the exact code, but can get it tested again and posted if needed). Looking for any and all ideas. Thanks in advance.

It could be a whole bunch of things, and then again only a few, how many miles since a tune up, if you can'r remember the last time it was tuned, start with plugs and wires.