I'm with you. I'd be reluctant to buy another sensor as well.

I think you need a little study on how that sensor is wired. The two white wires are the heater wires. They get powered from fuse 4. That is where you'd expect to find 2.5 ohms cold. It sounds like they are not getting powered.

The 0.5 volts is, or should be, on the black wire referenced to a good ground, like that braided jumper between the cam cover and firewall. That is the sensor output, but when the sensor is cold the 0.5V comes from the ECU, not the sensor. Just slip the green wire part of the connector apart, and you'll see which side has the reading.

Fix the heater power, and you'll probably fix the problem. If you let it slide, the default limp-home rich setting will soot up your expensive new sensor quickly. Also, if fuse 4 is not passing current, you don't have any tank pump.


--
Art Benstein near Baltimore

Everyone seems normal until you get to know them.