Hi. new to the board and did a search on A/F Gauge installation. Everyone seems to be installing them to the back of the PCM. Which wire is the correct one for the hookup on an 03 Avalanche? I followed Autometers direction to connect infront of the O2 sensor wire in my exaust but the guage seems to be reading backwards. It seems that it keeps reading Lean when I know it should be reading rich. I used the solid purple wire in front of the rear O2 sensor on the passenger side. This O2 is actually after my Y pipe so it is reading both banks at the same time. Any help would be appreciated.

Thanks

Bonedog

 

tha rear sensors dont read A/F ratio. They are only to let the computer know the cats are working properly. Pick one of the front ones. They read A/F. Dont worry about reading both sides, they are the same with our fuel injection. Only time they would be different is maybe a missfire or something.

Welcome to the Forum by the way!

 

Ok thanks. What wire color should I use? Solid Purple or another color. I do not have access to a manual or wire diagram. Don't feel like frying anything. Thanks for the welcome by the way.

 

Mine was purple, so i supose your should be too.
Purple is, or used to be the universal signal wire.

 

Thank you. I will be doing the change later today. Thank you very much on a fast reply. Great site you all have here and I will be checking this site everyday for more info and new info.

Thanks again

Bonedog