I have seen that kind of behaviour, when was working on a beta patch. It turned out that spi communication between two side got broken for a split second and that`s the time when the random errors pop out, and some scrambled data.

Do you have logs?

I suggest it could be bad tune, or some serious grounding issues in the pcm, bad pcm, or electric interference. Pcm dont like grounding at the chassis. Only acceptable ground points are at engine block, close to knock sensor and at ignition coil module.

Try bench testing the pcm to reject bad tune and bad pcm options.