Where is the easiest place to hook the o2 sensor wire into for a AFR gauge. I dont wanna run it all the way to the sensor. And I only have 3 o2 sensors, its a 8.1L. No cats. BUT no sensors after the cats

 

Do you have a narrowband gauge, or a wideband gauge? And which one?

 

its narrow band, just cheapo from auto zone.

 

I don't have an answer for you then, I've never hooked one of those up. Kind of a waste of time & money, unless you just want the blinking lights.

 

Well actually I paid NOTHING for it, brand new. My buddy works at auto zone and any little damaged package is "given" to me and a few select friends. And I dont have the money for a wideband so its a guage to hold a spot till I get one. But I DO want it to work

 

the main thing I need to know is WHAT WIRE is it that hooks into the ECM from the stock o2 sensor(s)

 

Here's the wiring diagrams(5 sheets). The O2 sensors are on the 2nd page, and the PCM connectors are on the first and last pages. Hope this helps you out.