Great thread. I just replaced both IMT Sensor O-rings on my daughter's 2005 X-Type 3.0 w/93k miles. We do not have a Jag dealer in our small town. I found Ford Part #87072S91 is same O-Ring. (used on Lincoln LS among other things). Easy to replace top O-ring, bottom not bad thanks to info on this forum I slid it over the mounting bracket (outside face) of Sensor. No more vacuum leak, no more check engine light with P0171 and P0174 codes. Also changed fuel filter (very easy on this car) filthy... seemed to improve mpg's slightly! Good day!