I just changed my intake manifold. The #6 injector electrical connector seal (the little red rubber rectangular thangie) was so swollen that it jumped out of harness when I unplugged it. Is this an indication that the injector is leaking fuel into connector area? Should it be replaced? Should all 8 be replaced as a set? I did check all the injectors and they appear to be okay as far as pattern and operation, but all I have to check them with is jumper wires, throttle body cleaner, and a blowgun.