As stated, I have a 92 accord that when you rev it up around 3000 rpm and above there is a bit of chatter almost like something is loose. I have been unable to to find the cause and have tried egr port cleaning, fuel (as it sorta sounded like fuel ping), flushed the motor, even thought it may be carbon build-up. All of these things still leave me with the same sound, car runs perfect and noise has no affect on performance. Anyone have any ideas?