I've been experiencing BRUTAL gas mileage for a while now.  Many people on
the list pointed to the O2 sensor.  It's been replaced twice in 6 months.
I've noticed that the van runs beautifully when the O2 sensor is
disconnected.  When connected it occasionally hesitates, stumbles, loses
power, etc.  Also, when I drive over rough pavement or hit a big bump the
engine stumbles.  I'm thinking this isn't the sensor but rather the green
wire that connects the sensor to the ECU.  Any opinions??  How easy is it to
change this wire??

thanks
Chad 85GL