Hardest Code ever P0300

Good morning we have a 2000 GMC Sierra 1500.  It has a 4.8  The truck was running fine all of a sudden it shut off very rough idol scanner came up P. 0300 and also the mass airflow sensor. We bought a new airflow sensor, actually changed spark plugs, wires thinking that was the problem. Everyone you speak with has a different opinion bought new fuel filter. Still doing the same thing got a can of Cleaner sprayed for vacuum leaks nothing cylinders 1357 when I pulled the coil wire off none of them on that side made any difference in the engine idol.  We took this job on to help out a family in need it’s been almost a month can’t figure it out. The scanner says fuel trim numbers are super high.

One entire bank of cylinders is not contributing, did you verify spark, fuel injection control and compression?

Probably worth a exhaust back pressure test, could very well be a failing/clogged cat. converter

I bought a spark tester and it shows spark on all of them. I took out the injectors yesterday cleaned them put in this morning same thing high negative numbers

I would agree I would agree with Noah and check compression

definitely check compression and also graph o2 sensors. as a sticking lean o2 can flood the entire bank

Kdubb2448 wrote:

I took out the injectors yesterday cleaned them put in this morning same thing high negative numbers

This is not the same as  verifying injection control.
Looking again at your captures, most of those trim pids don't apply. There's no stft3 or ltft4. Those are probably just place holders with no real diagnostic value.