2005 infiniti g35 reccuring p0345,p0011,p0021

So I’ve been fighting this code for quite some time now. At first I replaced the camshaft position sensor and I did this 5 times thinking I received a bad sensor 3 of the sensors caused a no start and the other 2 allowed me to start it but it was a long crank time. So I took it to infinity stealership and they did a vacuum test along with a fuel pressure test and oil pressure test. They told me It would cost me 1800 bucks to fix and they wouldn’t disclose the issue to me so I paid the diagnostics fee and ran. Now I just purchased this vehicle and upon discovery the camshaft position sensors connectors were spliced in I thought to myself well maybe they didn’t secure it enough so I redid it myself then wrapped the wires in 3M super 33 tape. Went to crank it and no go. Car started up and idled fine then once the radiator fans kick on it begins to bog down and the rpms go from 750 down to 400 sometimes even 200 then jumps back up to 750 then once the fans turn off Boom idle back to normal. If anyone here is a infiniti tech or been through this issue please chime in. TIA.