Hello all. 3.5L Accord with 246k. Blinking CEL misfire in cylinder 1,2,3,5. Been happening for a year. Once a year it’ll blink and run very badly. I replaced all spark plugs, coils, timing belt. Some plugs had oil on them bad, some didn’t. Nothing fixed it. I’m about to replace all the CATs. Then injectors are next. What could be causing all this misfiring and cat threshold codes? Thank You!!