O2 wiring question
O2 wiring question Wiring isolated ground sensors on my swap and had a question about the low reference wires. pins 25 26 28 29 and 63, which ones do I actually need and does it matter where I splice them IE in the harness, close to the sensors, close to the ECM?
Thanks
Thanks
You didn't state which pcm or harness you are using. I'm assuming a GTO harness? Pins 25 and 28 are for the rear o2 sensors and can be removed from the harness if you are not using cats. Pin 63 is for low reference on the oil pr which can be removed as well if you are using a separate sensor and gauge. 26 and 29 are for your front sensors and need to be there. It doesn't matter where you splice the harness to lengthen them just don't lengthen the sensors wire on its pigtail.
LT1swap is a great help if you aren't already using it.
https://lt1swap.com/2004gto_pcm_pinouts.htm
LT1swap is a great help if you aren't already using it.
https://lt1swap.com/2004gto_pcm_pinouts.htm
It is a 2000 5.3 harness from a sierra. Square white connectors for the O2's. What I am seeing is that tan 26, 29, and 63 need tied together, and purples go to bank 1 66 and bank 2 69 for fronts. So basically I can tie the tans together anywhere, pink fused ignition power, purples to their respective pins, and ground the blacks anywhere I have a good ground correct?
Thanks
Thanks
Last edited by buckeye79; Oct 21, 2021 at 02:15 PM.
Done- I spliced 29,26,63 right at the blue connector which is mounted under the dash. That way I only needed one tan wire coming out of the harness. I then split the tan wire in the engine bay section of the harness to each of the front sensors.
