Apparently not.
O2's only measure the Oxygen not the fuel. A misfire would read lean as you'd have 1 cylinder's worth of oxygen passing through.
1 plug misfiring would add 25% to the bank which on 128 would put the BLM's upto 160+
If that's the case you have at least 1 each side not firing & plugs would be wet.

MAF starts at about 15gms and drops down to about 7-8. Not sure what stock runs, I'm in SD but 7 looks a bit low so it presumably is getting enough air from somewhere.

What manifold have you got?


Mitch