UPDATE 2: OK, spoke to soon

Problem is back. Had another mis-fire at 18 degrees F! The usual shaking and bucking up and down.

Had to turn her off and re-start. She started OK the second time, but now the SES light is lit up all the time. Steady light. How much $$damage$$ are we talking assuming it's the oil separator? Will the $tealer take an arm and a leg?