Yesterday our Fusion threw a P0130, upstream o2 sensor code. I cleared the code, but it came back today. I know many times a CEL for an o2 sensor doesn't always mean a bad o2 sensor. But looking at some of the Fusion forums, this does seem to be a culprit from time to time, and a new o2 sensor does fix the issue. Sometimes it looks like this code could be associated with a vacuum leak, gas tank leak, etc. This car has already eaten 3 canister purge valves, before Ford updated the purge calibration last year during a TSB. When those have failed before, a different code has appeared, so I don't think that's it. As far as a vacuum leak, I haven't done any work to the car recently and I gave everything under the hood a once-over the other day. Driveability seems the same from what I can tell. Any suggestions before I replace the o2 sensor?
'11 Fusion SE 2.5L - 75k miles - Havoline ProDS 5w20, FL-910s
'08 Sedona LX LWB 3.8L - 117k miles - Peak conv. 5w30, XG9999