At 05:05 PM 1/6/2016, Richard Golen wrote:
>for a couple of minutes. Drove home and then disconnected the wires
>to the O2 sensor. Took the van for a drive. Ran like a champ for
>about 5 minutes, and the loss of power, rich running, etc. started
>up again. This is the first time its run this way with the O2 sensor
>disconnected.
>
>
>When it "idles" its runs roughly at 300 rpm and puffs out black
>smoke. I've blown through 1/2 a tank in 80 miles.

Find and clear the short to ground of the sensor wire.  It's probably
where the shield ends on the bright green wire.  The insulation tends
to crack there because of the sudden change in stiffness, and it get
shorted by loose strands from the shield.

You should have about 0.45 volts on that lead with ignition on and
sensor cold or disconnected, measured with digital multimeter.

Yrs,
d