The thing that goes on top of the injector. I got my new lines installed on the driver's side bank (much bigger pain than I would hav guessed), but I don't have a timing adapter thing for injector 4 so the line is too short. I installed the line from the previous set (only #8 was bad) but it kind of threw everything off. The number 2 line will not go on now and the number 4 line is pressing ******* 6 and 8. I would like to use the regular line with the adapter if someone can point me in the right direction.