... seems to be the reason why I can hear loud injector ticking noises from outside the car (with the bonnet closed). All the other injectors are quiet compared to this one.
If I replace the injector with a brand new one, presumably that would solve the problem? Do I have to replace all four injectors at the same time or can I just get away with changing this one?
They are the standard yellow injectors on a C14SE by the way.