is there a way to blank o2 sensors so you dont get warning light? 

Have you got an odb scanner ? Least you can clear it. The only other way I think is to have it mapped out

yeah i have scanner mate, but it keeps coming back, so instead i thought of deleting it 

OBD scanners dont work, only way is a remap to over ride the code for the sensor im afraid.

Ebay has loads of lamba sensor foolers, but i will say, fooling a lamba will affect the fuelling and in turn either make it run rich , or lean, both exceptionally bad for your car.

If you are referring to the post cat o2 sensor you could remove sensor from the exhaust and plug the hole with a bolt and secure the sensor so that it reads the atmosphere. The eml is caused by the second sensor reading the same as the first sensor so the ecu thinks the cat is knackered. This has worked in the past for me when decatting my mates cars. As long as the second sensor is reading different you shouldn't have a problem