wheatdad

Hey guys, looking for some insight on an ongoing spark plug issue. Over the past couple years had a lot of misfire, ignition coil problems, to the point where I had to replace my cats because of being destroyed by the unburnt fuel. Anyhow, things have been much better, however I seem to be fouling the #5 & #6 plugs with some frequency. Any thoughts on what might be causing this on these particular cylinders?

Thanks!