What's up everyone? So I have an issue with my 99 gt. When cold it runs fine. Once engine starts to warm up I can't get heavy in the throttle and starts to cut back around 4 or 5k rpms. If I ease into it gradually it will go as high as I take her. Hammer it and cuts back between 4 and 5k. At times seems like it doesn't matter what rpm I'm at. And has rough or irregular idle at times also. Like I said though it seems to only act this way once the engine starts to warm up. Any advice or input...

Cuts back under heavy throttle and rough idle.