Let us know how you make out in the end...we are kind of derailing this thread from what it was intended, LOL (sorry guys!). To me, it seems like the CPS would cause issues in the other 5 cylinders besides just cylinder #3, and you would likely see some sort of CPS related OBDII codes when you scan (if the CPS was the problem). What are the theories as to why it is only happening in cylinder #3 and how would it relate to the Injector circuit malfunction for #3? Doesn't make sense to me. My advice is to stay the course of what the PCM is telling you. Clear the codes (get a cheap device that can read and clear) and try correct what the codes tell you, for the ones that keep coming back before replacing anything else. If you keep getting the "P0203 - Injector Circuit Malfunction - Cylinder 3", then this is very likely the cause for the very specific Cylinder #3 misfire that you initially reported. If you have seen different additional codes since then, or if one of the initial codes has gone away and not come back after what you have done so far, then that will be valuable information as you troubleshoot further. Stay the course and you will get her fixed up!