Hi-Ho, Hi...02 sensor?

Well, I finally got the 2002 Sonata LX 2.7 inspected last month.
It's been driving fine, but on the way home tonight, the CEL came
on. I put the scanner on it when I got home, and it said:

P1134 Manufacturer Control Fuel Air Metering

So...I Googled, and am little wiser. It looks as if I may need an
02 sensor. Should I replace it? Or clear the code and see if it
comes back? Anything else I should try?

Could it be I have "summer" gas in the tank (I haven't filled it
since Halloween)? It's now 20F here.

 

Check for recalls first. There's a voluntary recall reprogram availabl
for this. If it's already been done, then you'll need the bank on
(firewall side) upstream oxygen sensor