I have a 2011 XF Supercharged, A few months a go while evacuating from a wildfire (I live in California) It was extremely smoky and we were stuck in traffic when the care stalled out. It started up again after a few minutes and was fine (obviously this could be completely coincidental A couple of weeks back when it started stalling out again (unfortunately I wasn't driving it either time but my wife says as she was coming to a stop the car would stall.
I've taken it into my local Jag mechanic and there are unable to figure out the issue. It's not showing codes and they are stumped.
Any suggestions greatly appreciated.

Thanks,

 

Perhaps this has already been checked, but did the Technician looking at the vehicle inspect the air filters?

It may also be necessary to clean the MAFs if there is soot accumulation.

 

You're in the X260 forum for 2015 models onwards. There's a forum n this site for your X250 model where you may find more help for your issue.