I have a VE SS manual with an L98 motor that has done about 175,000 km. Recently the check engine light came on and the stability control has switched off. Previously, I have had it throw fault codes and supposedly, the issue was the voltage dropped in the battery. The mechanic looked at it, took if for a run. On the first run the problem was there, on the second, it was not, so his best guess was a voltage drop. It did this for two days and then went away. That was two years ago. Now, I have misfire codes for the 8th cylinder. a) I have checked the battery and left it on a charger overnight to make doubly sure. b) I have checked the coil and ignition lead with an inline spark tester – they seem fine. c) I threw some injector cleaner into the engine and have run it for a while. d) There are new spark plugs waiting to go into it, but I am also waiting for a new compression tester to turn up as I want to check the compression before I put them in and don’t want to do the job twice. I want to check the resistance on the injectors but I can’t seem to separate the electrical connector on the injector itself. There is a grey retaining clip on the side, which comes up, but what am missing. Is there a push tab or something to release the connection? If somebody could describe how to do this for me, it would be great. If anyone has had similar fault codes, what were the causes of the problems?