If you caught what I originally posted before my edit, you're welcome. I mistook his P code for another that I had seen recently. I think he has a vacuum leak at idle and it seems like he has checked all his bases, I remember having a oil cap kick my *** one time and I believe it was for a similar or possibly exact issue. Turns out his O2 sensors were plugged in backwards , once the vacuum leak was fixed he would have started getting codes for O2 sensor delay and unknown subfault. If you have my original post saved before my edit, feel free to post it, it will explain the slow response and unknown subfault codes.