>>  The O2 sensor is not working correctly. It shows an
>> erratic output ranging from 0.3 volts to 1.8 volts.  The readings don't
>> change when the mixture is enriched with the fuel pressure regulator.
>
>Sounds like a bad O2 sensor.
>
>> The engine runs the same when in open the O2 sensor is connected or not.
>
>That is correct. Your O2 sensor is shot. Since your 02 sensor is not
>putting out a voltage that is in an acceptable range ( according to what
>the ECU expects to see), it simply ignores the 0s sensor input.
>
>TomC

Wait a minute. If the O2 sensor is producing voltage, it is, at least
minimally, OK. Increasing the fuel pressure will only make the reading go
higher. Also, there must be a problem with your measuring methodology,
because an oxygen sensor cannot produce more than about 1 volt, no matter
how rich the mixture.

Joshua Van Tol -- jjvantol@lear.csp.ee.memphis.edu