I had the same problem after installing my HD oil cooler on the '99 Ultra. Sandwitching the piece that directs the oil to and from the filter is the problem. It brings the filter out just enough so it contacts the sensor before being unscrewed all of the way. Being a trusting soul , I figure that no one would design such a unit without taking the clearance thing into consideration, so it must be something that I did wrong. I elect to contact HD. Ended up speaking to a gal in their tech dept who thoroughly understood the problem I was having, and assured me that I hadn't done anything wrong. That, in fact, that is the way the cooler was designed, and yes, you have to yank the sensor each time you change the filter. Mind you, I am certain that the innovative folks who inhabit this forum have come up with ways to circumvent this phenominum, but what I just relayed was the MoCo's answer to my querry.....