Could be anything including an injector that bled down washing the cylinder out. I had that happen one time on my truck, it cleared up after a few minutes, hasn't missed a lick in probably 70,000 miles since.
They're known for cam sensors, the harness under the covers as mentioned, and low oil pressure from diluted oil can make them run rough.
I'm hoping for the cam sensor.
Now-2014 Sierra 346RETS 5er BUB
Then-2002 Keystone Springdale 286RLDS TT
Nights camped in 2014-28, 2015-127, 2016-10