Now I'm really confused. The diagram is from realoem and I gave the last 7 digits of my VIN to get to it.

When I look down at the engine, on the passenger side I see the front one (part #1 in the diagram) which looks to be relatively easily accessible, and the rear one (part #2 in the diagram) back under the microfilter housing towards the firewall.

The code would seem to indicate that it's the rear, harder to access, probe that needs to be replaced. But it looks like a number of things have to come off to get to it.