Peugeot 206 GTI walks in 3 cylinders

Will it be the coil or any bad position sensor?

Well, if you were more specific in your fault, could we help you better, any fault code ???
Most likely it would be a damaged cable or the coil, I do not think that any sensor because if all the cylinders would fail.

Peugeot 206 usually fails the coil, this does approximately at 80 thousand kilometers, this coil is complete is embedded in the spark plugs is like a spark plug ramp, but an eye can be a problem of spark plugs and nothing more, if the escapes should throw a p0300 code failure in a cylinder or fugitive current in a cylinder. luck

Thanks for the fact but check it well and had some cut cables that enclose the coil and there it arranged the same thanks