An update: still here in Palmdale, but we did get the truck back today. The main issue was a split o-ring on an injector.. Oil pressure controls fuel injection, and the oil was getting past the o-ring, getting into the fuel injector. Basically, the engine on that cylinder was burning oil vice gas. After many $$ spent, the car is now hitched up to the trailer and ready to be taken back home tomorrow early morning.
We had hoped to leave today (Friday), but the shop reported a check engine light late last night. That was due to a fuel line that was weeping fuel. Once that was fixed, the shop experienced a power outage for 2 hours and delayed further checks to ensure everything is good to go.