I just acquired a 99 SS M6 and it has a texas speed 224r cam and btr pushrods. Melling HV oil pump, bbk headers and Y pipe and a ls7 clutch. I had a code for injectors. I fixed that by replacing said injector and had a knock sensor code and I did the same with that. I had a misfire at idle from day 1 and after fixing these issues I still have that misfire but no codes for misfires at all. Anybody got some ideas here?? It's a misfire at idle and it's a pretty big one. Thanks in advance