High RPM Backfire when fully warmed

Well a backfire can happen because a few different things. I would recommend checking the spark plugs first and getting an idea of what the overall tune looks like. You have to also take into account how you drive and how you have been driving the car. You could have some carbon build up temporarily causing an issue. You haven't even mentioned if this is under load or if you are in the car in park operating the throttle with your foot or what.


Could you provide a little more information?