Just recently my 1999 XJR Engine Failsafe Mode light has been coming on but only after the car has not run for around 3-4 hours. I have no code reader and the dealer is asking about $150 just to look at it. Any ideas, I know it could probably be a million things but, if there is something specific I should look at I'm all ears.

 

Several things can set a failsafe mode so the OBDII codes are really the starting point.

Most auto parts stores, at least in the US, will read the codes for free. Most will not reset them anymore due to legal considerations. Some have a 'loaner' program that includes a code reader then you can reset the codes yourself.

Return with any codes you may have and we will try again.