Might be worth a shot to clean it with map cleaner first. On our bmw version it is in a portion of the intake passage (which can be removed by loosening a clamp at each end of the assembly) before entering the intake manifold. If you find a jag engine picture on line it should show up and will help you locate it . Ours has the same codes but I think I have a vacuum leak as ours has not likely been apart. Someone will be along shortly to give you the definitive answer.