Well, it's not P0206. You only have 4 cylinders, so a fault in cylinder 6 makes no sense.
It could be P0102 with the addition of subcode 06.
P0102 = Mass or Volume Air Flow "A" Circuit Low
But that's the official definition when the car complies to EOBD, which it doesn't.

I would suggest reading the codes with a Ford specific scanner to be sure.