So I did the built-in diagnostic and I get 5 flashes. Is it correct that this is the exhaust gas recirculation error? Please advise if not. Now that I have that I have reset the CEL light. Is there any reason to build a reader and read the individual pins? I suspect this is all the wiring harness acting up since I can see the insulation crack up on the thermostat housing connections. The signal earlier this summer was injector 1 ground. That light was reset by a tech and then came on about a week later and has been on for a couple months. Now it is reading EGR. Is this likely the harness as I suspect? Thanks. At least I can turn the light off now.