Need Help!! 05 Rx8 Running Like Poop.

So I just shipped my 2005 RX8 down to Utah from Alaska and when it got here I took it for a drive and after it gets to running temp it starts to run like absolute garbage and loss of power. Periodically while driving the check engine light will flash. I did a obd2 scan and it comes back to rotor 1 misfire. I have replaced the coils plugs and wires, I even replaced the fuel pump as mine is the original with 118000 miles (motor only has 25000 miles) but I am still left with ****. Compression test was done last month which came back to 7.9 8.0 7.9 7.9 so I know it's not an engine issue. What on earth could it be? I am so lost I don't know where to turn. P.S. catalytic converter was also replaced last week.