Can one cylinder be affected by a bad pcm board or all would be?

What is your question?

I changed my catalyst both of them with new gaskets and o2 sensors replaced coil pack on 4th cylinder because it misfired corrected that issue changed valve gaskets were leaking new spark plugs put in move working spark plugs and injectors that worked to cylinder 3 still nothing checked compression it's good checked for spark it's good I'm out of ideas and this code didn't come up till I fixed cylinder 4 which is weird so now I'm lead to believe it's pcm board? The first misfire didn't happen tell gas tank got filled up 5 mins later started the first misfire on 4 but if gas station had bad gas wouldn't it affect all cylinders? The only one that is missing now is cylinder 3 any help would be appreciated thank you