Coincidence

Tipping around town earlier car started to missfire,wouldnt rev up etc.Drove away fine while not under load.Checked power fc all sensors fine,little or no knock.32kms ago had to put €20 of "normal"shitty petrol in it as local e5 station was empty.Its going fine again and i just put e5 into it 10mins ago.Is this a normal reaction to sub 99 octane petrol(mapped for e5) or maybe another problem somewhere.

Could be poor quality petrol alright, the octane rating wouldn't make a difference unless you were hammering it and getting high knock levels