I'll Be Watching You!
Join Date: Jun 2011
Location: Forked River, NJ
Model: Mercury Sable Wagon
Engine: 3.0L 24v Duratec V6
Rep Power: 74
I had a P0156 and P1151 pop up on mine recently. I havent dug into it to see what the problem is yet, however I know my pan gasket leaks so that would be the P1151, as far as the other I'm betting it's the sensor that's bad.
being that both are on the same bank in your case I would do as Sheila said and inspect the wiring to make sure nothing came loose.
'01 Sable LS Premium Wagon Duratec, 99 Dodge Durango 318 V8