Interestingly I decided as the failed sensor was broken then I had nothing to loose by flushing it out with brake cleaner. Once flushed I left it to dry in the sunshine and plugged it into the car and to my amazement the reading has come down from 4.56 to -0.48. Whether it works correctly or not when back on the car I don't know but if you have a faulty sensor it's worth cleaning it and possibly save yourself a wad of cash
