Fabia MK1 1,4 16v 2005 - thorws p0321 in rainy weather

Good day fellow Skoda drivers,
 

I have recently bought a nice Fabia Mk 1 - 6Y5 1,4 16v with BBZ-engine as our no. 2 daily runner beside my super Yeti. Engine around 200K full service
& well maintained by Skoda - just been fully overhauled with oil, airfilter, timing belt change etc.

My wife drove home some days ago in very rainy weather and she noticed sudden a power loss, hesitation and stumble and some of the warning
lights came on. Very abruptly and into limp mode.

When arriving home I could see it had logged a 16705 - P0321 ignition/distributor engine speed input circuit-G28: range/performance - DTC status Sporadic.
 

I erased the codes and we haven't seen any of this for 4 days now. Very strange!

 G28 = a faulty Speed sensor?   But then the code would have come back so I'm inclined to believe wires or water some where? Or just a hick-up??

Does any of you greaty fellow Mk1s' with the 1,4 16v BBZ engine or similar have any idea of what this could be?? Before I start to change sensors etc..

BTW Great forum with tons of good info...  thanks for allowing  us Scandinavians to join as well...

Many greeting from Denmark

Christian