HI Richard, and Welcome to the Club. I would suggest trying the David Manners group, who do supply new parts and are Jaguar Specialists, as well as other classic British makes. What you will find on their site is a great parts catalogue , which will assist you by giving a guide to the price. I picked up a part there in June, and took it to a member in Loughrea, Co.Galway which saved shipping costs! I use an OBD2 scanner which cost me £20 which seems to work OK. You can then look up what the code means. The Computerised system with the Mongoose connection is highly thought up, and I would have bough one but for my laptop being a MacBook Pro for which you have to buy additional software. Let us know how you get on. Regards, Peter.