When revving engine in Park, to a relative hi rev, engine generates repetitive hesitation action. Acts almost like a machine gun. Check engine light has come on, but is now out.

Engine seems to idle okay, with no hesitation, even with some acceleration appears to be okay. But, for now, the problem occurs at hi rev.

When driving there maybe an occasional hesitation, but not always.

Anyone have any thoughts as to what may be causing this?

Take me back to the '60's and the good old muscle cars!!