[Tiamat-red]

Ok, so here's my problem. About a week ago I started throwing code, 22. Right knock sensor. And 2 days ago I got a code 32. Right O2 sensor reading odd.
Now I have an A/F gauge. Just your average "ping pong" type Autometer one, but good enough to make guesses by. Of course I had it running on the LEFT O2 sensor...
So I hooked it up to the right one and sure enough it was running lean...way lean.
Which I assume could account for the knock sensor(I had hoped it was a bad knock sensor, but maybe not)tripping.
So, I checked the fuel injectors. All good.
I replaced the FPR with my parts one.
Started it up and still lean.

This morning however on my way to work it was fine. "ping pong" through stoich just like the right bank.
And then on the way home the same. Right where it should be.
After I got home however I started it up(within 10 minutes)and it was back to lean.
Actually threw another code again.
Shut it off and started it up several more times and it wouldn't leave "lean".
So it seems like once it warms up something causes a lack of fuel?
Until it cools off.
Could this be a bad O2 sensor?
I had read here that a slipped timing belt might cause a lean condition, but I don't see how restarting it when warm would relate.

Any help would be appreciated, as I don't want to go throwing codes and detonating after every time I get gas and start the car again...