Next time you change oil and it is drained, loosen the fitting so there is some space in the outside rim, wipe the oil away and squeeze some RTV into the crack around the outside. Then tighten back and it will never bother you again.
Are you running synthetic or thin oil? It tends to find ways out of an engine that thicker oils dont.
sometimes the sensors come apart too much to fix. new ones are not that pricey (or just plug it). The Shape went through this recently and had to plug his, as i recall.