Thanks Art. You didn't have to remove the throttle body? Hmm. Will have to struggle to get that boot back on somehow.

I don't think this will prove necessary in my case. I just tested the thing again by back-probing the blue wire and reading voltage with the key on but engine not running. The air temp here is 66 degrees and the engine is stone cold.

I get a reading of 1.0 volts. If I understand how this works, the higher the temp the lower the voltage. Last time with engine warmed up from running other tests (but not hot from actual driving) I got .45 volts. I have read that if the sensor is not working at all to expect a much higher voltage - like 4.5 volts.

So I am thinking that, like the pressure regulator, this isn't a likely suspect in my rich running condition.

Cheers