Dodge Repair: Truck Barely Running

Question
Hello Roland, I'm not sure if this falls under your expertise, but I am really hoping I can get some advice as to what could possibly be wrong with our truck. I need as much help as I can get. It's a 2000 Dodge Dakota, with a 4.7 liter engine, V8, 4WD, Automatic. It's very important to us to get this truck up and running again. We just got our other vehicle going, now the truck is acting up, and unfortunately my mother totaled the other one just as we got it fixed. So we need our truck. I'm not great with mechanical issues, but I'll do my best to describe the problem. It seems to have lost all power. Most of the time it can't make it over small inclines in the road. By 'small', they're not even as steep as a speed bump. If we're lucky, it may get up to 5 MPH and go for about a mile and a half. The steering wheel is extremely tight. The engine makes an angry, growling sound, and often cuts off after a few minutes, then it takes twice as long to get it to start again. But it seems to idle fine. It's really sucking gas. It's only getting about 2-3 gallons per mile, and the smell of gas is strong. The RPM drops when you give it give it gas. My father used to be a mechanic, so he does have some knowledge on this. Here is a list of things he's already checked and knows these are not the problem: Fuel Pump, Camshaft Position Sensor#brand new#, Crank Position Sensor#also brand new#, IAC Motor, Spark Plugs, Coils, Injectors, MAP Sensor, Timing Chains, O2 Sensors; Emptied the Converter and cut off pipe; Used a smoke machine on the intake and found no leaks. We've replaced the ECM twice, as well as the plug to the ECM. The only code that comes up is P1391#the reason we just replaced both cam and crank sensors#, and it only comes up sometimes. There aren't any obvious leaks. It's unusual for my father not to be able to come up with an answer, at least to me anyway, so any suggestions you might have would be greatly appreciated. Thank you for taking the time to view this - Faye

Answer
Hi Faye,
The earliest truck manual I have is for 2004, so there could be something on the truck which is not covered in that manual.
I did check the 1391 and about the only possibility given the sensors were replaced is that there is a wiring problem which the manual suggests to examine the wiring harnesses for the sensors, and then to check by viewing the outputa with an oscilloscope to detect whether that faulty pulsing is present.
The other item I believe is often overlooked, but which may not be installed on the engine, is the exhaust gas recirculation valve which can get gummed-up and fail to close tightly. So if there is one you could try checking its action and lubricating the valve stem with WD-40 while moving the stem back and forth by hand. The '04 doesn't have an egr but possibly the '00 does.
The '04 manual gives some ideas about non-monitored problems, beyond what has been replaced and checked by your very capable mechanic, as follows;
fuel pressure, spark plug wires, engine compression, an injector sticking open (wet plugs), clogged or restricted air cleaner inlet or air filter, restricted or leak in vacuum assisted devices, poor grounding of the ecm.
I hope that one of these possibilities will help out.
Please read the PS (below) and respond to it.
Thanks,
Roland