I have an '04 Neon SXT MTX and am trying again to connect my A/F gauge. Since it has a dual o2 sensor, I determined that the best bet for accuracy would be for the upstream sensor. When I connected the sensor wire to the sensor wire on the connector to the upstream o2 sensor, the A/F gauge just pegs at the max. I have let it warm up and run for 20 minutes to ensure that the engine was at normal operating temp, but no change in the gauge. Any ideas on what the problem could be?

 

what color was the wire you used for the seding unit to the gauge

 

On the upstream connector, I spliced into the 20 gauge Black/Dark Green wire. Thats the wire that it specifies as the o2 signal wire in the wiring diagrams.

 

most a/f gauges you need a after market o2 senser even the mopor ones