saxo furio oil leak - found but need help

[shane1234567]

the car is a 2001 y reg saxo furio 1.4

well every time i start the car its dripping oil. well looked under there and found the leak

its from a sensor its a green top sensor right near the bottom lambda sensor, what i need to know is there a copper washer or rubber o ring that sits on teh bolt part of teh sensor that i can replace so i dont have to replace the full sensor

any help would be great and pics sorry i can upload a pic for some reason

but the sensor is green top, 2 pin i think, right by the bottom lambda sesnor. and obviously its oil at the other end lol.

[shane1234567]

any 1 ??

[shane1234567]

found out it was the oil switch and it had a small amount of damage hence the leak,

bought 1 from the scrappt for £5 and its all done