After doing some googling some other things that popped up with this code were:
MAF, vac leak, PCV and the fuel filter as Cam said.
Scotty:
Fuel economy has been ok, well as good an an M35 can be. Have not seen a spike as such.
When you mention the O2 sensor do you mean the one on the dump yes? If it was this would it not effect both banks not just throw up an error on bank 1?
FYI: The issue came about from normal driving conditions in peak hour, not giving it much stick at all. When I got home I checked the fault code and then cleared it, ran the car for 5-10 min and it has yet to come backl.
Cheers.