Hey guys thanks for the add. So hopefully i can get some help from you guys on this issue. So basically i did full tune up all 6 coils and sparks. I replaced all 6 fuel injectors. I replaced both catalytic converters all the way back to muffler and muffler itself. I replaced o2 sensor bank1 sensor 1. So the nitro was working fine for a day and check ingine. Misfire number 6 and o2 sensor bank1 sensor 1. So i replaced coil and sparks again and also o2 sensor. Now it keeps misfires number 6 and 02 sensore again. Car shakes not crazy but you can feel it. Any suggestions would be great. Thanks in advanced guy's.