I had the same problem with my 40hp Evinrude! Take a piece of tape and mark your oil reservoir,see if its using oil,check your plugs and see if they are rich or lean,if they are lean,i would be very careful,it might be the oil pump failing! So ur sensor might be doing its job,thats the last thing you need,detonation of your cylinders because it was leaned out! GOOD LUCK,STEVO!