Ok. Just got back from taking the Car to Bob located in Long Beach, CA.

He was very knowledgeable and ran numerous tests but couldn't find much initially. Then he unplugged the EHA valve and found it made almost no difference to the idling condition which was strange -- meaning the EHA is either A) Not functioning properly B) Not receiving correct information from the O2 sensor.

And B) is the most likely cause as I have said before that the O2 sensor must be tarnished from the oil consumption that I had before (even though it is working because I am getting volts out of it). His machine although said that the O2 sensor's readings were a little out of whack.

So replacing the O2 sensor is my number one priority now. I think that we may have solution in hand!!

What's the best thing I should do now? Buy new/used or get a 1990 mustang 3 wire bosch sensor (I understand they work) from the local store?

I have another EHA valve that came with my fuel distributor, but Bob said its highly unlikely that the EHA has a problem.

Also, are there any articles online on how to change the O2 sensor? My Haynes manual does not mention it anywhere. Is it difficult?

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