Taking it to a mechanic would be great.. it's my daughter's Tahoe that I gave her couple years back.. the value of the car verses what I'll likely spend with a mechanic done way out...I know that's where it needs to go but honestly at this poi
Here are couple videos showing spark color and amount of spark..and noid light for injector pulseI would recommend doing a cranking test and then pull a couple spark plugs and see if they are wet with fuel nodes smell like it. That will help direct your diagnosis as well. I'd maybe inspect 2 before trying this: burning them clean with a small torch reinstall, test crank a couple times, and then remove again and inspect.
If they are covered in fuel, then you know spark or air is gone (it runs on starting fluid, so I'm suspecting air is OK). If there is no fuel coating or smell, then you have a fuel problem.
I'm not ruling out the PASS LOCK, but like stated above, you'd need a better scanner to dig into that one. Hope this helps!