I have a 2003 XJR with 185,000 miles that is having frequent Engine Failsafe Mode issues. The car will basically need to be turned off for a few minutes then runs fine for another several days or even weeks. It happens at all times of the day or night and the error also says something about Traction Control Unavailable. The error code is P0430 and I was told by my mechanic that it is probably the oxygen sensors but another person told me it was most likely the Catalytic Converter.
Any ideas??? Thank you

 

there a lots of things that can cause the failsafe mode issue. on my car it was a problem throttle body unit. There are lots of threads on here about the failsafe mode problem

there are a few good threads in here:
https://www.jaguarforums.com/forum/x...k-links-20090/

good luck