Would the RCM be throwing its own code? When reading codes it randomly goes from cylinder to cylinder but the only codes are cylinder mis fire. I ruled out coil packs since its random and all cylinders. Is that a mistake? Also plugs and wires for the same reason. I feel it must be something simple I am over looking. I read the post on rcm repair and will be contacting tighed1 this week. Seems like a good idea even if not my current problem. Thanks for any input and help.