12.7 questions

Ok. Some of this, I am learning as I go. Not out at the truck now. In town researching. Just saw a video on you tube. Says you can turn computer to not show specific codes. I remember the people I bought this truck from thought there was a "weak" injector. This might explain. Why I was not getting codes on my ecm. See for me the Holy grail is the explanation and the why. The new ecm is registering the codes that are logical. Pwm fault. Etc. I don't know much about inside the engine, and I guess there is no opportune time to learn. As far as prior work? I took the truck to Detroit. Hoping they would get to the bottom of this. Then to my buddy across town. He had no computers, so we did the best we could. Truck seemed ok. Leased the truck. Stopped by my place to grease, etc. Before going to work. Truck got CEL just as I came into the place I work on stuff. I shut truck off and tried to restart. Do not pass go. Do not collect $200. As no codes, I originally thought fuel. And oh, my! We were were going through the fuel system for days! Lol. Now, I am pretty sure we got fuel like donkey konk. I found an article that showed you how to troubleshoot cam/crank sensors as I had changed those at my buddy's and later got one SEL code 42. Then last Eve, I caught up with my buddy and borrowed an ecm it is very close to what I have. Now I see code 62/63. Pam fault. And a different one but am concerned about why Pam. Ideas? I am researching.