The plugs have thick soot around the ceramic, I can wipe it off and the plug would be like new again. The plugs have no deteriation, just soot from running rich. I’ve only had the very vague P0300 Multiple random misfire and after fixing the vacuum leaks i had a MAP Sensor High input value which I think popped up because of the better vacuum. I cleared it and it hasn’t returned. I also swapped the MAP Sensor from my wife’s impala that does run good and it had no effect. I’m starting to think that it could be the crank Position sensor but I’ve had no code for it. I’ve heard of them being bad without tripping a code.