I need to know what is the signal wire coming from the pre-cat O2 sensor to the pcm. I am putting in an efie on my 99 dakota 318 (for the hydrogen kit I am installing). The wiring diagram told me it was a orange and tan wire, well I check the voltage on it and it reads around 4v. Now it is a possibility that the O2 sensor died when I attempted to clean it with some electrical contact cleaner. (with my scan gauge 2 it know reads after the clean 0 for short and long term fuel trim and is always stuck in open loop) But would a dead sensor cause a 4v reading?

any help would be appreciated

 

Well I got my fuel trim back by replacing the sensor.

 

this post isnt gonna help at all....but i love your truck.....BAD ***

 

Thanks lol