Reduced Power Mode

[Doubeleive]

fuel pressure?, throttle body, maf are things that come to mind for me, typically reduced power mode is a throttle body fault, but low fuel pressure could cause your symptoms as well and that is not something that comes up as any code you would need to check it and/or monitor it with a gauge.
you can get one of those bluetooth OBD adapters and run a app like torque that will allow you to monitor what the vehicle "says" it is.

 

[Geotrash]

New recent event - 6 seconds of WOT, then highly sensitive throttle inputs and extreme surging if I even thought about increasing power. Drove 3 mile on the freeway, then took the exit and when I rolled up to the stop light the engine wound down and died. Re-start resulted in stumbling engine and if died. Same result over several tries. Finally got started and put in gear, drove a few blocks home and shut down. The net morning I disconnected the negative battery terminal, removed and cleaned the MAF sensor and reconnected. All runs perfectly now for two days. Did I fix the issue?

My guess is you fixed it by re-securing the battery cable. The low voltage warnings were a useful clue.

 

[Rygrego]

My guess is you fixed it by re-securing the battery cable. The low voltage warnings were a useful clue.

+1.