Yes one spark plug was especially clean. I will stick my borescope through the plug holes and see if I see coolant in any of them. As for the lean condition...even if there is excessive fuel, there is a higher ratio of air to fuel. If the mixture is way too rich to ignite, the oxygen and fuel from that cylinder will pass over the O2 sensor and O2 sensors only read oxygen. Since that oxygen was not burned at all, it would mimic a lean condition. I've read this in a couple places and it makes sense if you think about it. If it were to ignite, the oxygen would burn and there would be a rich reading. The injector from cylinder 1 is definitely stuck open a little bit. I can blow air through it but not the others. The filter baskets in all but one injector were completely deteriorated, so I'm assuming a piece of the filter or gunk from the fuel ended up in the injector. Most likely from changing the fuel filter a couple weeks ago.

 

I got the sticky injector to work consistently after using an ultrasonic bath and pulsing 12v through them. Also, I was right to suspect that the timing on bank 1 had slipped (pic below). I reset the timing and will report back later to say whether or not I'm still having problems.