X350 rear outer universal joints replacement
 

Hi. After spending the last week looking for a rear off side universal joint for my x350 2003 xj6 petrol which is showing abs / dsc fault lights on dash. Had codes read and says rear off side abs sensor missing a tooth. I have looked at reluctor ring and all seems ok no missing tooth. I am looking to replace the whole outer universal joint with new ring fitted but am finding it near impossile to find new or used / reconditioned part for my x350. My questions are why would code reader say tooth is missing when it is not and does any one know where I can get a cheap universal joint from in the uk? Also will any other jag parts fit ie s type or x type?
Many thanks in addvance.