I was able to get a replacement fuel distributor that came off a working 300e. Installed, and adjusted the duty cycle and it seemed much better. Held at about 50%. Let my son take the car to work, about 5 blocks from home. This morning, I checked on the car and found the CEL on and the code 17 for O2 sensor. Cleared the code and hooked up the dmm and found that once again the duty cycle is going rich or lean but not holding. Played around with it, got it to hold at about 50% again, but with higher revs, it goes to rich and pegs at about 12.8v. I jumped the O2 sensor and took the car out for a test. At idle, the sensor is swaying as it should between .86v and .01. But with acceleration, it goes to .95v and stays till the revs are dropped.

I don't understand why each time I make a change, it seems to run good for a while, and then goes back to this rich mixture. It also would seem to be quite a coincidence that both replacement fuel distributors would be bad to the same degree. Is the O2 sensor still good once it sets off the cel and I reset it. Could it be the EHA?