I have converted a number of FS2002 and FS2004 aircraft to CFS2 and make my own panels for them. A problem that often arises with jet aircraft is that often EGT, oil pressure and fuel flow gauges don't work.
For instance with the Fox Four Korean War F-86 (I don't use the included panel, I have made my own) the oil pressure and fuel flow gauges work but the EGT gauge does not. I have found that if you add air file 540 and 1501 the EGT works but the oil pressure and fuel flow then don't work. So it appears to be a matter of having the correct air file components in the air file.
This looks to be too complicated to resolve by trial and error. I wonder if anyone, like Hagar the Guru of CFS2, would be able to shed any light on this.