Steve, thank you for your post! I am a bit undereducated regarding the CIS-E injection however after reading some of your previous posts regarding similar matters, I believe you are basically concerned that I have a oxygen sensor working within the system. That is one thing I have not swapped out since I bought my 86' 300E, however, there is one in the car. Could this really be causing my troubles of high load, high RPM power loss? I was thinking that my issues were more along the lines of an ignition or valve timing issue . Also would you recommend the 3-wire mustang oxygen sensor retro-fit? Thanks!