My workshop checked my car thoroughly and could not find what is causing the rough idling in my car. They finally suggested that they change the ECU unit( I am not too sure if that is what its called) This unit cost quite a bomb new. My question is can this ECU unit be repaired? If not can a good used one be used instead. According to my workshop it cannot be done as the computer units are programmed and must be made to suit the car. Being such expensive equipment i am sure Jaguar should provide some form of warranty. I would appreciate some advice from anyone who have experienced this. Thanks. Syed