0.5 volt dc battery to fool O2 sensor?

[GasSavers_Erik]

I have been driving around watching a digital multimeter which is tied in to my one wire oxygen sensor wire (87 civic with feedback carb.)

The feedback system seems to be doing its job (readings jump around but 90% of the readings are below .45 volts when cruising on the highway). When I floor it, readings jump up to 0.8 and when decelerating in gear, readings go down to near zero volts.

I want to fool the system into leaning the mix out a little, so if I could just feed 0.5 volts into the oxygen sensor wire, then the computer would think it was running rich and tell the carb to lean it out.

Its the same theory behind the "fever buster" mod that is listed here on the intake temp thread.

So, I figure that all I need is a good low amp DC 0.5 volt source that will mimic a rich mixture oxygen sensor signal, but won't have enough amps to fry the computer.

Any ideas from the electronics whizzes here? How about if I use a 1.5 volt battery and a ton of resistors in series, might that be safe?

I am not looking to do this long term, just for a 30 mile test run.

Thanks in advance for any help.