While all of the new parts you have recently installed might seem like they would eliminate many potential sources of the running problems, in my opinion, they are MORE likely to be the source of the problem than something you didn't replace; that, because either there is a connector or ground not quite secure, or because the new parts have failed. Board members have occasionally found that even good, name brand electronic parts are not what they used to be.

In other words, do not eliminate something just because it is new.

The 'scope discussion is beyond my experience, and possibly overkill for diagnosis, but I bet Art B. could answer those questions.