TPS voltage?

Does the EGR valve have a control solenoid? Check to see if there is constant vacuum to the EGR valve, that would keep it open all the time, it might not be the valve itself but the solenoid (EGR Vacuum Regulator (EVR) could be bad or since its powered from the ECM and ground side controlled, if the EVR control wire is grounded it would stay on all the time, applying constant vacuum. But trying the delete trick is faster and can rule out the entire EGR system with that one test.
I was going to suggest the smoke test, but since youve already done that,
this is a diagram of the vacuum, PCV, and vapor hoses if needed.

Okay, did you notice any difference with the egr blocked off? It might be its control solenoid thats having the issue if its leaking vacuum somewhere. I will need to go through these codes again but your are not getting the 41 Lean code now, instead its a 42 Rich code. 33 is EVP not closing properly. 25 Knock not sensed during this test. 73 I'll have to check.

So no TSP codes now? The Knock sensor also shares the Ground with the sensors that have been setting codes. 21 ECT out of range. 12, 13 RPM out of spec. But the Lean code being gone tells me something with the EGR control solenoids or lines was leaking air in.

No worry on the delay, we need to know what some of these sensors are reading, or at least what the PCM is seeing for sensor data.

You have code 21 (ECT out of range) listed?

A coolant temperature out of range can send the PCM rich.

Okay, we need to know what the ECT is actually reading, are you comfortable back probing the ECT connector when the truck gets up to operating temperature. But at 68f degrees the ECT resistance should be 31,700 to 42,900 Ohms, so thats about room temperature.
But even better are these Pinpoint testing charts for the ECT (diagrams 3-6) they are more specific when it comes to resistance measurements at certain temps, and youre absolutely sure there is close to 5volts on light green/yellow wire when the sensor is unplugged (key On engine Off)? They have you go back to the TPS to check the 5v Ref, but it should the same as what you read on the TPS's 5v wire. Im posting this information because coolant temp sensor is one of the main inputs for fuel strategy, engine temperature greatly effects how much fuel the PCM is going to add to the mixture and we need to figure out why it keeps setting this code.
Even after a new sensor, the PCM is now seeing a rich exhaust reading from the 02s, its just difficult when we're not able to see live scan tool data, we dont know what the PCM is actually seeing, so reading actual voltage readings from sensors is what we are limited to. We could have you create a vacuum leak to see if the mixture returns to semi normal, but there is no way to see the PCM initial reaction to adding air in. And if there is wire corrosion anywhere in between the sensor and PCM it will effect the sensors range, this applies to either wire. You mentioned 85 ohms at one point, thats something Im concerned about, I dont really know what you were checking at that point.
I see only one 02 sensor, so that is how the PCM is detecting whether the exhaust is rich or lean, and will compensate accordingly. At this point I would have a scope lead on a bunch of sensors to see how they are reacting, but that isnt possible.

Just curious, does this truck still have a catalytic converter? Or has it been hollowed out or anything like that? Continue with your ECT testing, but I wanted to ask about that.

So you're back to a 41 System always lean again. And this is still with the EGR valve blocked off? You're not beyond your depth, the codes setting are the indication as to what's happening, have you been driving the truck or is it just idling while you're doing this testing and it still has a high idle currently? Let me know what its doing now.

The oxygen sensor voltage is how the PCM is reading a lean or rich exhaust, that's its feedback sensor for the mixture. I understand it's frustrating, imagine having to figure out these issues every day, that can really get to you, but with the EGR blocked off, I'm going to repost the vacuum hose diagram, and I want you to block off the vacuum hoses I have marked. They are mostly the EGR control lines coming from the intake manifold, The rich lean codes coming and going are kind of pointing to the oxygen sensor voltage being stuck or responding very slowly.

When that happens, first check to see if you have lost spark, that's an easy quick test, if you still have spark, then pull a couple spark plugs easy to access and see if they are covered in gas and flooded out.

If an engine is flooded out, in most cases you can put the gas pedal to the floor, this allows a lot more air into the engine, and it should start. We will keep it simple for now. Just check those things for me.
It might not be flooding out, let's start over here a bit and check for spark once it stalls out.

The ECT, being out of range, is going to cause the PCM to over or under fuel the engine. The engine requires more fuel to run until it warms up,

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

https://www.2carpros.com/articles/stall-at-idle