Update: Ran 2 tanks of Husky 94 with Sea Foam motor treatment in each tank. Also ran a can of Sea Foam spray through the plenum. Once all that was done, I re-flashed to AlpineMSS 91 octane Stage I tune. So far, knock on wood, so good. The knock seems to be gone when lugging the engine and I no longer have any knock over 4000RPM.
So thanks again for the advice.
One last shout out to Alex - he was an awesome help!
