[Goat Blower]

Torqueing the knock sensor isn't that important, and won't cause the problems you're describing. It sounds like you've already got it in there just fine.

If it's carbon build-up on the pistons, letting the MCCC soak should take care of it. Make sure to change your oil immediately afterwards since you've just washed your cylinder walls down.

When I had "phantom knock", it was from dirty lifters. It wasn't audible like you'd normally hear, but it happened to be in the frequency pocket that the knock sensor picks up. No need to buy new ones, just pull yours out, let them soak in a bucket of kerosene overnight, then take each one, spin the top til the two holes line up, and blow it out with some compressed air. Compress them and put them back in, they should fill with oil in 30 seconds or so once you start the engine.

A faulty knock sensor could also be causing this, but I'm guessing that's the first thing you looked at.