UK Car Repair: XJ 8 1998 VP, air flow meters, faub

Question
I have recently purchased a 1998 Jag XJ8 VP model- It has 80,000 miles and is still pretty decent- We have had the fail safe driveability message 'amber' light come on four times now (in two weeks time) Is this a sensor problem or something more serious? It does not appear to have any loss of power with the light...???
Also I would like to buy another set of keys and faub- but it appears that the dealers charge about $500+ for the parts and programing- ouch!
Any suggestions?
The car is very sweet and my wife loves it... Have I purchased a lemon? I see that there was a history of problems with the 1998 models (from other forums...)
DCC

Answer
Not a lemon, it is 10 years old!  The early 4.0 engines had many problems, throttle bodies,  Air flow meters, nikasil cylinder coatings AND  defective chain tensioners.  Some of these things may have been rectified, check the car history.  You will have to scan the computer to see where the message originates.