Try removing the air filter and wiping the oil around the throttle body butterfly/sensors - helped me and the light did not come back...
Is the oil coming from the air filter being oiled sprayed excessively?
The oil comes from the crankcase breather that vents into the throttle body. If it's been standing for a while it can burp a noticeable quantity of oil at start up and it can even drool down the front of the engine from the air filter.
