Theres not many things that could obstruct the passages to the point where you'll throw that code, it would spin a bearing quick. And a sure sign of this being the case - you'll here knocking and the engine won't run for more than a few minutes before you deprive a bearing of oil.

Does it run without knocking and clanking?
Can you verify the car does in fact have oil pressure?
Did you check for continuity at the pressure sensor & wires, like the helms states?

If it runs ok, I am willing to bet on the pressure sending unit or wiring. Good luck.