P0300, p0301, p0506...Rx8 idles bad at cold start but after warm up acts normal.

New here and seek wisdom. I got these three codes this morning, i looked for similarities in other threads that have this but doesnt seem that anyone has a difinitive answer. I see people with the same symptoms. I change the plugs coils and wires and it idles really bad on warm up as if only one rotor was firing then like a minute later the idle goes up to 2k but still misfires. After its warm it sounds normal but feels under powered. Could this be the cat? Can someone give me a difinitive answer?
2007 rx8
56k
6 sp.manual
Thanks