I've got Berk HFCs and they constantly throw errors, some people seem to get them some people don't I reset them sometimes, I've had spacers on and off doesn't make a bit of difference it's just life. I've pondered if there's some oil in the mixture, I do burn a fair bit of oil so I was pondering fitting a catch can and seeing if that helped. I've had the cats 6 years now so it's not terminal or anything, never had any other issues.
Can't be bothered to buy new sensors that as far as everyone says are totally redundant. There's apparently a dummy circuit you can fit and then delete the sensors or even have them turned off at remap time