These are your grounds:
Tranny (from negative battery terminal)
Engine (from T bar/head light bracket to valve cover)
Wireing harness (near thermostat)
I think what he's reffering to when he says Oil Pressure, guys, is his VTEC Oil Pressure?
Is it the Green plug on the Passenger side of the head Icoy22?
It will run fine without that plugged up, but you will indeed throw a CEL code. (#8 i think... i'm too tired to look)