A/F Gauge Hookup

[Hemi99]

I am stumped, to say the least. I am trying to install an Air/Fuel Gauge into my '04 Neon SXT. Ran into a snag when installing it, I tried hooking it up to the Upstream O2 signal wire and the gauge pegs all the way at rich completely, never moves when the gas pedal is moved. I tried hooking it up to the Upstream O2 return line and the gauge pegs all the way at rich immediately and when the gas pedal is applied, the needle drops just a bit down from full rich. Any ideas on what could be the matter with it? I let the O2 sensor warm up and everything, still no avail on it. If you click on the links below, I have provided the schematics and wiring diagrams for the '04 Neon (from the MOPAR Service Manuals). Which wire should it be hooked into? Any assistance would be greatly appreciated.

http://www.wzrd.com/~johng/wiring1.jpg

http://www.wzrd.com/~johng/wiring2.jpg

[MagicRat]

Hmmm....maybe the O2 sensor is bad or your car's EFI is running way too rich. Either way, it is possible the gauge is hooked up and working properly.

[Sluttypatton]

Also, most stock O2 sensors are narrowband, and are wildly inaccurate any significant distance away from 14.7:1. It may not even have to be running that rich in order for the O2 sensor to peg at full rich. Try hooking it up to the downstream sensor just to see if the gauge will read differently there. Measuring at the downstream sensor is not very useful in the long run however, since the cat will have already cleaned up the exhaust, but at least it may help determine if the gauge will function. If the downstream sensor gives a reasonable reading, you may want to check your upstream sensor, it may be bad. Try the downstream sensor and get back to us, that may at least give you a point of reference to start trouble shooting from.

[Hemi99]

The O2 sensor better not be bad, the car only has 900 miles on it! I will check into your suggestions this weekend and let you know. Thanks again!