Have you or have you not physically verified that the sensor on your truck is measuring actual oil pressure, and is not equipped with the 6psi switch the rest of us seem to have?
Sag2 says its the same from 2003-2010, I don't have anything to say it isn't. The FSM calls it a switch\sensor and states it monitors oil pressure. I can't find anything the says it does NOT monitor pressure.
Question; Considering the cost of the item, is it realistic to think it is a switch only?
If these trucks don't have an oil pressure sending unit, then the lack of an oil pressure reading is not, in and of itself, an indication of a bad ECU. That's my whole point - do not write off the ECU based on the fact that a nonexistent sensor is not producing any data.
Your missing the point, completely ignoring HOW the data stream for oil pressure is generated, if it is missing it IS a potential problem.
The scan tools indicate that data should be there. IIRC there are several of the monitors on the market that allow tapping into some of the streams the ECU outputs.
Is the data stream fake or real, doesn't matter. If the ECU should be putting it on the data port bus and it is not, why?
Better yet, is the scanner he used actually 100% compatible and capable of reading all the data streams. If not, what ELSE is it missing?
The OP didn't say his oil pressure gauge was non-functional so SOMETHING is going to the cluster controller in the form of a data stream. Is that the same data stream that is supposed to go to the data port?
The OP replaced the injectors, these trucks normally respond pretty well to new injectors for hard starts, still have a hard start problem that is solved by ether or roll starting.
Could it still be mechanical? Yes, cross over tubes, CP-3, etc, etc,etc.
Could it be electrical? Yes, batteries, battery connections, ECU, ECU harness, ECU connectors, etc, etc.
Again, given the problems that surface when the ECU does not respond to commands from scan tools, does not output expected data streams, you can't rule it out or in.
Whether or not the oil pressure semsor\switch does\doesn't measure pressure is truly immaterial.
