Originally Posted by npccpartsman
If you're running a tuner then fuel pressure is critical with or without a regulated return. Oil pressure will basically take care of itself in that if you lose oil pressure the engine will shutdown anyway. EOT and ECT can be read via the OBDII port where as fuel pressure must be added since there is no sensor.
All in all it also depends on what you're doing with your truck. If you're towing a lot then the temp gauges are the most critical.
Well in all honesty, it would have been better for him to get a DashDAQ and what isn't monitored thru the OBD-II, he could have gotten analog sensors run thru the DashDAQ and gotten EGTs and Fuel pressure that way considering he could have also gotten boost and trans temp thru the OBD-II(and 460 other sensors) as well.
I would argue that having an ECT or EOT is also critical if he is running a tuner and has stock headbolts as getting to operating temp is really the best before he starts ragging on the truck with the tunes. In that case, I would say that EOT or ECT is as just as important as Fuel PSI if he is running a tuner and it is really important even if he isn't running a tuner because you can still rag on a stock truck before it gets up to operating temp and blow headbolts as well.